Take a look
here
In essence it states
"What Are guarantees?
A guarantee is what it sounds like. It is an assurance from the manufacturer or vendor of a product as to its quality and suitability. Under the terms of a guarantee, if the object which you bought breaks down or stops working within the lifetime of the guarantee, they will repair it for you, or replace it free of charge. Most guarantees are for a year or two.
But Don't I Have Those Rights Anyway?
Yes. Under the Sale Of Goods Act, you have statutory rights which state that any goods which are sold to you must be fit for the purpose they were intend for. If you have a watch, and after a year it stops working, it was obviously faulty and not fit for it's purpose. You can, therefore, take it back to the shop you bought it from, even if you don't have a guarantee.
Even better, under your statutory rights, you can demand a refund, while a guarantee only entitles you to a repair or replacement.
What Are guarantees For, Then?
Vendors and manufacturers often use guarantees to confuse customers, and cause them to overlook their statutory rights. In many cases, a guarantee can also add value to a product, and make it seem more attractive. A large number of products now come with guarantee certificates, which must be signed by the person selling you the product, and in most cases, the salesman will not do this without being prompted to. This means that the guarantee is invalid, and if your product breaks a few days later, you may be told that you don't have a valid guarantee, and so nothing can be done about it. In cases like this, many people forget about their statutory rights.
On the other hand, some guarantees are useful, as they may be longer term, and therefore add to your statutory rights. This is because after a few years, or 'reasonable use' your statutory rights will expire, and the law may take the view that any damage to the product has been caused by 'fair wear and tear'."
Go get your replacement or refund