Extremely poor service from Cupboard Warehouse

How do we stop businesses like Cupboard Warehouse from ripping off unsuspecting customers? Our high gloss cupboards doors were damaged during installation by their employee when he used a blade and dirty rag to clean them. Shaun had promised to have the damaged doors replaced. One week has become almost one year and we are still waiting. He doesn't answer my calls but when I call from a different number he answers so it is clear that he is avoiding me. After close scrutiny I know that I am not the only victim of this unscrupulous businessman.