Damage to vehicle

in Feb 2015, I took my vehicle to Glasfit, to fit a new front windscreen. When I fetched my vehicle, I found my hands free kit did not work. I phoned them immediately. The manager said, not possible, but he would get back to me, I had to follow up several times over the next couple of months, eventually saying that if it was age or any other issue not attributable to them I would be happy to pay. They then directed me to a sister company, who inspected my car, and indicated that Glasfit had cut the wires to my hands free when they installed the new windscreen and they were liable. However, there were a series of long weekends coming up, and the part had to be ordered. I, once again, had to follow up several times. I was unable to make the appointment to repair the hands free and the agent agreed to send someone out to fix it at my work premises. I have had to follow up over 15 times, and have spoken to everyone at the branch and have had several promises for them to come and repair my kit. EIGHT months later, I still do not have a hands free kits that is working. Absolutely no service what so ever.