Just a general comment about buying and returning items which are faulty in the warranty period (from anywhere covered by UK laws), you shouldn't have to pay for the shipping costs for returning them:
Distance Selling regs, A Guide for Businesses on Distance selling:
"If the goods are faulty or do not comply with the contract, you (ie the business) will
have to pay for their return whatever the circumstances."
http://www.oft.gov.uk/shared_oft/business_leaflets/general/oft698.pdf
