overcharged for GPS
I rented a car 1 way from Naples to Catania a few months back and was told the GPS was included but id have to pay a 1 way charge on 25 euro by the dollar representative in Naples. In catania, used the quick checkout as there were (no lie) about 20 people queuing as 2 flights had just landed from the UK. Once I got home, I saw 89 pounds deducted from my card and on challenging them on this, they said it was 11+ euro a day for the GPS. As I have no document to prove or disprove what was said to me in Catania, is there anything I can do about this? Maybe asking for a refund via my credit card company?