Builder's Warehouse refuses to replace broken blinds.

I ordered roller blinds from Builders' Warehouse, made by a company called Finishing Touches. When the blinds arrived, it was in a totally unacceptable condition. 1. The top square channels are bent. 2. The colour ordered was mahogany, however the top and bottom channels are of a different colour to the louvres in the blinds. 3. Finishing Touches just stuck a mahogany coulored louvre with tape on top of the different coloured channel to supposedly match the colour of the louvres in the blind. This is also bent. 4. The mecahism used to lower the blinds and pull the up is hanging halfway out of the top channel in which it is supposed to be housed.

Builder's Warehouse is not interested to help me out by either fixing this mess, or to return my money.