Hi there, this is an open and shut case. You are due £350 (Assuming your home airport is indeed in the UK) for denied boarding under EC261. As your flight actually operated, you you were denied boarding, and there are no exceptional circumstances here for the airline to not pay you. You need to file an EC261 claim with them. Please let us know what airline it was. In addition it seems like you spent 24 hours extra in Rhodes. Hope you enjoyed the day? The airline already paid for the hotel so that's good. They also owe you all meals expenses from that day, as well as transport from/to the airport, so if you are out of pocket for this you need to gather your receipts and bank statements and claim for these separately from the above, under duty of care. In addition to the above two claims, you may have an additional £350 claim for your next flight being late. But here the departure time does not matter, it is the arrival time, and it needs to have arrived 3 hours late for you to be able to claim. Do you remember the exact arrival time?