Poor Quality

My wife's car recently picked up a vibration. Taking the car to a Tyre fitment centre to have the tyres re-balanced it was discovered that 3 of the tyres shape had being deformed. The tyres fitted where Khumo Tyre's which Lombard are the agents. I did contact the branch in Pinetown and spoke to Ryan. He asked to have a look at the tyres and deduced that this was caused by nails therefore nothing can be done. I find this a poor response since this happen to 3 tyres and no attempt was made to have the Tyre further tested, These are important parts to a motor vehicle which endangers lives but Lombard's don't care attitude means these are less important issues to them. To clarify if nails were responsible for this problem why were the tires not losing air? The car is an Hyundai i10 and the tyres were on the vehicle when it was purchased from Hyundai Umhlanga.