I ain't no expert but on the telly the so called experts are always banging about your contract is with the dealer not the manufacturer.
Go back to the dealer and claim your statutory rights and go off on one with them about fit for use etc.
Local radio consumer program will soon have that one sorted for you if the dealer don't.
Take notes of quotes for future reference, I put my phone on record and leave it front of them for a bit of intimidation, that usually prompts a favourable response.
Good luck init?