Glasfit - worst service provider ever!!

Glasfit Roodepoort Branch (011) ********** replaced the windscreen in my BMW in August 2018. A day or two after they had installed the windscreen, the windscreen started cracking. the crack appeared from under the rubber at the base of the windscreen. I have phoned them numerous times, they have made appointments to come out and look, they have promised to phone back but never do. This saga has been going on for nearly two months and they still have not made any effort to rectify their mess. Their service is shocking!!!