hc is spot on.
Goods have to be of merchantable quality, fit for the purpose for which they were supplied and last a "reasonable" amount of time. The retailer, not the manufacturer is responsible for making good under the Sale of Goods Act.
Furthermore (although you should not need anything further) there is also an EU Directive covering this issue and it is along much the same lines, making the final seller responsible to repair, replace, or provide a full or partial refund (the choice resting with the customer) if goods fail. I think the minimum period of cover (i.e. the "reasonable" time the goods should last) under that Directive is two years, though it is suggested that some goods may be expected to last for up to six years.
If they try to fob you off contact your local authority's trading standards department.