Assuming your supplier is a GGF member, maybe get in touch with the GGF, and see what they reckon? They have a customer charter which their members are required to follow, and they offer an arbitration service for dissatisfied customers of their members.
It may be that just mentioning to your supplier that you're dissatisfied and intend to take the matter up with the GGF will encourage them to get a little more co-operative.
You might also want to do some looking into the consumer protection legislation, been a while since I looked at it, but I seem to recall there's some stuff in there about products having to live up to reasonable expectations.
