Dont let B&Q fob you off to MacAllister. Your contract is with the retailer and you have every right to reject the item if it is not working properly especially after only a few weeks.
As "Good Luck" says below, B&Q do not make things - they're a retail outfit - they buy and sell.
MacAllister is a brand name exclusive to B&Q - pile it high and sell it cheap stuff made by random Chinese manufacturers and sold with once respectable badges on and enjoying next to zero support.
XXX, June 2016