Last summer I rented a car from Maggiore Car Rental in Sicily and I took a full insurance coverage on the car.

On day 3 of my holiday when I was sleeping somebody reversed into my car on the hotel parking lot and the car sustained sever damage. The hotel staff was very helpful - they took a statement from the driver who cause the damage, called Maggiore to arrange for my car to be towed away and a taxi to the nearest Maggiore location so I could get a replacement car.

At the end of my holiday I dropped the car off before the Maggiore office opened (early flight). A couple days after I came home I saw that Maggiore charged me �800 extra (presumably deductible for the car damage) plus some assorted extras totaling �120 - no idea for what.

I sent them an email plus a registered letter - no response whatsoever.

I tried to dispute the charges with my Visa issuing bank. I've never disputed a charge before, so I am not quite sure how it works. The bank told me they noted my complained and now I need to pursue the matter with Maggiore (which I've already tried unsuccessfully).

Any suggestion how to get this issue resolved?

What are you disputing - the €800 deductible, the €120 extra, or something else? What is the grounds for your dispute?

I just rented from Hertz Italy and they were quite clear that the damage deductible was my responsibility unless I purchased the Super coverage.

I am contesting both.
The coverage I bought from them reduced my liability to zero - so no deductible whatsoever should be charged.
If somebody charges me more for rental (�120) they should tell me why. The price was fixed.

Perphaps all can be sorted/explained or perphaps I am wrong and I should be charged. The problem is that the company does not respond to any emails/letters.

i thought there were some damages that were not covered particullarly in a european contract: engine, transmission, undercarriage, tires and wheels.

I'm afraid they may be right, if you didn't fill in the 'CAI'.
In Italy we have a form, 'CAI - Constatazione Amichevole di Incidente', that drivers may use to report details to insurance companies in case of traffic accidents, especially when drivers agree about the description of the accident itself, of the damages and such. It's a sort of standard form for joint statements. Car rental companies and insurances may require that - even if there's no agreement or it's only your own report - drivers shall fill in and deliver that form, in order to report damages.

I think this is the case at Maggiore:

"La responsabilit� del Cliente per i danni subiti dal veicolo noleggiato pu� essere convenzionalmente ridotta ulteriormente o eliminata del tutto, salvo il caso di dolo o colpa grave del conducente, sottoscrivendo l'opzione "Eliminazione / Riduzione Quota di Addebito Danni" (SKO).
Le speciali condizioni di applicazione dell'opzione SKO sono disciplinate nel Tariffario Maggiore.
Il canone di noleggio � determinato tenendo conto dell'inserimento di tale patto di eliminazione / riduzione quota di addebito danni nella misura indicata nel Tariffario Maggiore, con riferimento alle singole categorie di appartenenza del veicolo.
[...]
Nel caso di incidente subito o procurato dal veicolo noleggiato, anche qualora il medesimo non subisca danno, � obbligo del Cliente darne comunicazione alla pi� vicina agenzia del Locatore entro 24 ore dall'evento, redigendo ed inviando il modello CAI, in mancanza diverr� inefficace qualunque limitazione di responsabilit� sottoscritta dal Cliente (CDW, SKO). Il Cliente � altres� responsabile del danno subito dal Locatore a seguito della omessa o ritardata comunicazione, e si obbliga sin d'ora a corrispondere a titolo di penale l'importo indicato nel Tariffario Maggiore, salvo il maggior danno. Per maggiori dettagli si veda l'intera Documentazione Contrattuale."
http://www.maggiore.it/it/condizioni_generali.html

Roughly: if you don't report the accident within 24 hours to the nearest Maggiore office, by delivering the CAI form, the full coverage doesn't apply.
The € 800 charge seems consistent with this scenario:
http://www.maggiore.it/it/doc/TARIFF...AUTO%20ITA.pdf

Do you remember if the statement was based on the form above? If it wasn't, a simple statement is not enough and, thus, that may be the reason for the charge.
Edit: you shall get a copy of the CAI.

Dear Alice,

Thanks a lot for your detailed answer.

The accident happened in the middle of the night while I was sleeping. The hotel staff filled in a standard CAI form with the details of the driver who cause the accident. But the driver did not sign the CAI form (unclear to me why - whether it was a simple omission or a bad will). The hotel staff witnessed the accident. My car was parked, so there is no question of whose fault it was.

Maggiore knew about tha accident first thing next morning - they towed the car away and provided me a replacement car.

Perpahs the missing signature is the reason why I am getting charged (which would be pretty nasty taking into account the circumstances of the accident and the fact I had witnesses).

However, there is no excuse for complete lack of any response from Maggiore. Non existing customer service. We don't care, we don't have to attitude.

I can't speak directly about Maggiore since I haven't rented from them, but when renting from other agencies I usually elect to add the Super CDW to my contract. This add-on cannot be prepaid and can only be purchased at time of pickup. It's a per day charge of $6-$9 or so. There are zero exclusions and a zero $ deductible. When asked about the "full LDW coverage", they told me there still was a very hefty out of pocket deductible. Perhaps they were mistaken when they told you that your full insurance had a zero deductible?

I'd be interested in knowing who offers Super CDW that low in Italy. On a one week Hertz rental a few weeks ago, the Super CDW was 140�, which works out to $27/day.

Ouch!!
May be the size/class of car causes a boost in Super LDW. I dug up the info from last rental in Italy and it was few years ago. The reservation was supposed to be an intermediate size car, which turned out to be a Chrysler PT Cruiser upon pickup. It was a prepaid booking through Auto Europe and the rental agency was Europcar Italia. Picked up in Piazzale Roma, Venice and dropped off in downtown Bologna 10 days later.
Super LDW was 6.67� per day at that time. The additional driver charge was a ridiculous 4.13� per day.
Do you think the Super LDW has gone up that much since then with all providers, or were you renting a premium car?

It was a Fiat Punto, which doesn't meet any definition of premium. It was a one week rental picking up at Roma Termini and returning at VCE airport. I can't remember exactly, but I think Hertz's Super was in line with the other Super quotes I saw.

I ended up declining the Super coverage and renting with a Visa Signature. FWIW, Amex won't cover car rentals in Italy but Visa Signature will.