There only if not fired line is bullshit. Your statutory rights say it has to be fit for purpose, which is firing bb’s. However problem is you’ve had it six months, you cant prove its not been used. If you can go see them face to face, let em see how clean and bused it looks. Perhaps they’ll change there view. Perhaps agree that if they fix it you’ll pay for some minor upgrades while there on. However if you dont trust em go somewhere else like Neg Earth.