Unhappy

Im so upset I went to BP garage in Goodwood Capetown for fuel and I asked the attendant to also check water for me and he appeared he did not close the lid and when I was on my way my car overheated and could not start I reported the issue to the garage they asked me to bring the car they checked their footage they checked their receipts as well they confirmed that indeed the can see the attendant opening the car but can not really see if closed it now my issue is them asking me to pay for the parts and engineering and them they will cover only the labour they are telling me they haven’t checked the car yet but they want me to agree to pay for parts and engineering …. Wheres the accountability in this? They have the evidence but still I must pay for theirs carelessness … I had no issue with my car at all now they want to shift the blame to me, I have spent money already for towing my car and getting school drivers as well since I don’t have a car