Car with chipped windscreen

On 26 January I collected a car from Upington Airport, the car had a chipped windscreen amongst other damage. I asked the people involved if it will be fine for me to drive to Springbok (nearly 400km further) with this car and they indicated that the chip might run but it will be fine. They had no concern for my safety or the road worthiness of the vehicle. I then requested them to give me paperwork on the damage and I was told that it would not be a problem as they know about it. I trusted them - big mistake. On 28 January I returned the car and was questioned on the chipped windscreen. I told them that it was there when I collected the car. I was answered with: \Impossible\". It was later confirmed and I received a verbal apology but I am very dissatisfied. Avis does not do their administration properly and then falsely accuse me after I trusted them. This should be resolved and I need feedback on future measures put in place to prevent placing me in such a terrible situation again. I found the attitude and service pathetic."