I was really suprised to see on the News the other day that if you have a faulty product within the first 6 months of purchase, that you are entitled to choose what action you want the store to take.
For example, YOU can decide whether you have a replacement product or indeed a full refund, apparently it does not matter what terms they have in place as the LAW superceeds all.
I have also been directed to the manufacturer of faulty goods on many occasion, where as it is the stores responsibility to rectify any faults as my contract is with them.
No idea what you do when the store disagrees, however, the following link explains more:
http://news.bbc.co.uk/1/hi/business/7490759.stm
KNOW YOUR RIGHTS!
Useful Links:
http://www.consumerdirect.gov.uk
http://www.need2know.co.uk/law/know_your_rights