Damaged my car and now screening my calls to avoid me

P.G. Glass mobile unit had an appointment to replace my windscreen, they confirmed that they were coming by phone as well as sms. My appointment was scheduled for the 6th of Feb 2018 between 13h00 and 14h00. Firstly they did not show or even bother to call, I had to phone them to find out where they were only to find out that they could not find my windscreen and they would reschedule. I then received confirmation that they were coming on the 8th. While replacing my windscreen they opened up my bonnet and damaged a pipe (no where close to the windscreen, you can clearly see the handprint of the glove the gentleman was wearing when he obviously leaned on the pipe (I have photo's). I then contacted a manager Etienne who sent someone out to view the damage. The manager confirmed the damage and still stated that they did not follow procedure as they were supposed to put some cover over my bonnet / engine when working which they did not do. He said he will take the photo's that he took on his phone back to the office and get back to me as they will need to fix the damaged pipe. I have phoned Etienne and left numerous messages however it is now almost a week later and he is not taking my calls or returning my messages. Terrible terrible service, I am so disappointed and will never ever use them or ever recommend them to anyone! I will be reporting them to my insurance too!