Glasfit no work after paying a deposit 2 months ago.

Glasfit Belfast has to be the worst company to deal with. They asked for a deposit to do work for an insurance claim, which I paid on 15 March this year. They have not done any work on my place as yet. They now refuse to answer multiple emails and their manager Jaco never returns phone calls. Last time it took them 6 months to repair a window frame and they still got it wrong and replaced the safety glass with normal glass. One has to wonder how a company like this remains in business.