INCORRECT BILLING!!!!

I had a hired car from first car rental, which was due to be returned on the 16-09-2015 and was meant to be picked up from my home address in Manor Gardens Durban, I waited for the drivers to pick up the car and nothing, I called the DURBAN CBD branch more than 5 times to find out if the people were coming to get my car and was told drivers are on the way! finally at 4.50 I get a call from the DBN CBD branch that they can no longer pick up the car as the drivers are lost however can I please drive the car to my work place in MOUNT EDGECOMBE and they will pick up the car there in the morning, as you may know that the car needs to have a full tank as well be washed and ALL of this was done for them, however I am now being pilled a petrol price because they tank was no longer full!!!whose problem is that??how do you ask a CLIENT to drive the car to MOUNT EDGECOMBE due to your lack of service and now charging the client the petrol it cost them to drive it there due to your FAILED SERVICE! on top of that I lay an complaint my case gets closed without any investigations I get a email saying I AM LIABLE end of story! the Manager Tarryn WAS NO HELP was so ever with her patronizing tone!!!