Shocking after sales service from Woodford Car Hire

On the 22 July 2019, we hired a vehicle from the Woodford car hire branch in Cape Town. Once we were told that we could pick up the vehicle from the attendant in the parking lot, together the attendant and I did a full inspection of the vehicle noting the damages such as 2 chips on the windscreen and other scratches on the rear bumper. The attendant marked all of these points down on his check page and we left after signing. At the end of the week when we were en route to the airport, o stone was flung up and hit the windscreen adding a third chip to it. When we got to the car hire drop off area we informed the attendant on duty that a stone had chipped the windscreen and he said "No problem, fill in the disclaimer saying that it was not your fault and you will not be charged for it." Well as it happens, they send me an invoice for a new windscreen for the amount of R 2 650.00 ex VAT. i contacted them immediately after receiving the invoice and they said sorry but it is not up to and employee to make such a statement. Subsequently I have asked for proof that the windscreen was replaced, the original documents showing the other two chips on the windscreen as well as the scratches that I had pointed out to the attendant when collecting the vehicle. It is now the 9 September and I am still waiting for these documents. By me waiting so long tells me that this company is de*****ing people by saying that they have replaced the windscreen at a cost but never actually do so.