Broke my fuel cap cover and refuse to replace

I would give minus stars if I could. Bp Garage at 33 Village Road in Kloof Durban KZN. The arrogance of the owner ..Dave.. is disgraceful to say the least. One of his petrol attendants broke the fuel cover off my vehicle and he initially offered to order and replace it. Today I get told it's my problem and I can't prove they broke anything. Disgusting! Will never fill up here again. People beware!