once again. government advice on the sale of goods act
http://www.berr.gov.uk/whatwedo/consumers/fact-sheets/page38311.html
there are a lot of laws to protect the buyer – which are onerous on the retailer which means a lot of retailers try to get out of their obligations.
However 8 months old means
After six months and until the end of the six years, it is for the consumer to prove the lack of conformity.
IE you have to show it is a manufacturing fault not that they have to prove it was not.
If it is a manufacturing fault then its your choice to replace or refund or repair. However
If repair and replacement are not possible or too costly, then the consumer can seek a partial refund, if they have had some benefit from the good, or a full refund if the fault/s have meant they have enjoyed no benefit
so if you insist on a refund you might well not be entitled to all your money back
The manufacturers warranty might give you more rights than the legal minimum but you cannot have less rights than defined in the sale of goods act.
Your contract remains with the retailer not the importer. If there is dispute over whether it is a manufacturing fault or not then it is not unreasonable for the manufacturer to be consulted.
Have a read of the advice and see what you think applies. Hopefully the shop will play ball but if not its always useful to know your rights.