As your original suite was obviously faulty your consumer rights are as follows;
A full refund or a repair or replacement.
However, the repair or replacement must be carried out within a reasonable time and without causing significant inconvenience to the consumer. If this does not happen or the repair or replacement is not possible, then the consumer can rescind the contract (claim a refund) or request a reduction in purchase price.These financial remedies can only be achieved by a failure of the repair / replacement option once acceptance has taken place. If the trader agrees to rescission, the amount paid may be reduced to take account of usage.
Once you have chosen a remedy and the trader has agreed, you must give the trader a reasonable time to effect the chosen remedy before switching to another one. Ultimately, if a remedy cannot be agreed upon, then the courts have the power to choose any of the remedies.
Ask the retailer to check out trading standards you are quite within your rights to DEMAND a reduction in price.
Hope this helps