Please accept our apologies for the issues that you have been having with one of our products, and for any inconvenience this may have caused.
The first year of the guarantee is held with the retailer, if you contact them they will be able to arrange a replacement for you.
If you purchased it through Amazon, your online account may say that the returns window is now closed. However, if you call their Customer Services team on 0800 279 7234 they will be able to arrange a replacement for you.