You should remove your booking reference - it could be used to personally identify you.

I have to admit, I gave up on your letter. The references to "hot humid air" and a "torturous 2 hour flight" won't win you any sympathy, and just make the nature of the complaint difficult to ascertain.

Additionally, it's not clear if Newcastle was your ultimate destination (you seem to say you needed to be in London the next day), and why you would choose such a round-about routing (air to Amsterdam; transfer to the ferry port; slow ferry crossing to Newcastle) if it was vital you arrive at a certain time. I would NEVER dream of booking two separate tickets - particularly with a change of mode of transport like that - without building in an overnight stay between them. There are several flights each day from Amsterdam to Newcastle (KLM and easyjet both ply this route) with the last KLM flight of the day being at 21:50. If you truly needed to get to Newcastle on this day, then you would surely have booked this flight, rather than apparently flying to London (it is not clear which day you flew to London; or why you didn't attempt to have Vueling fly you to London from Rome when it should have become clear to you that you were going to miss the ferry from Amsterdam).

You will not be able to pursue Vueling for compensation for your onward travel plans. Vueling's contract with you was to get you to Amsterdam; although they got you there late, they are in no way liable for compensating you for your missed ferry trip to Newcastle, or for paying for your flight to London. If you have travel insurance, you may be able to claim on this policy for the additional expenses you incurred.

However, I would advise you in future, if you don't want to plan your journey all on one ticket (and you could have flown directly from Rome to Newcastle with Jet2.com [summer seasonal service - if this happened in summer, as suggested by the "hot, humid air"], or with KLM/Alitalia all on one ticket from FCO to NCL, or with BA via LHR, etc etc) that you plan pessimistically. When you knowingly opt for separate tickets, you are therefore assuming the responsibility - and cost - of recovering from disruption to your plans in case of delays. Vueling's responsibility ends when they get you to Amsterdam - that you had planned further onward travel from there does not change things. This is why you must plan pessimistically - because when delays happen and interfere with your plans, you [and your insurance, if it applies] are solely responsible for paying for the new arrangements.

You have not said the reason for Vueling's turn-back - that you mention there was an ambulance waiting could mean it was for medical reasons, and therefore, Vueling would not be liable for ANY compensation for the delay. It's difficult to accept that the pilot would turn back, an hour into the flight, and not even inform the passengers. Do you now know the reason for turning back? This really is important - it could very well be that Vueling are not obliged to pay you anything whatsoever for the delay, if it was out of their control.

If you believe the reason for the delay was actually the fault of Vueling (though turning back to the origin would seem to indicate a major problem which would seem to indicate it was unavoidable), then you can perhaps get one of the many claims agencies to take up your case. However, they will not need to know about your missed ferry, further flights, etc - these can never be compensated by Vueling. Check your travel insurance for this.

As regards the lack of refreshments, I tend to agree that had they given vouchers for use at Rome Airport, this would only have contributed to the delay. Perhaps they could have waived the on-board food charges, but I think they did the right thing by not delaying the whole plane by sending the passengers off to have lunch in the terminal.

They certainly won't pay your overnight accommodation fees either! Once you got to Amsterdam, you are no longer their responsibility. Only if they had to delay the flight from Rome until the following day, would you have become eligible for overnight accommodation paid by Vueling.