Gym Membership Refund

I joined a local gym in August 2008 and paid in full for 2 years with my credit card. My daughter joined the same gym in November and I paid in full for 1 year with my credit card for her. On 2nd January 2009 they wrote to both of us to say that they were closing down on 15th January, and relocating to within 1 mile. They promised to confirm the reopening date and the new loaction at a later date. They have still not reopened and have ignored my letters so I have requested a refund via my credit card company. The gym have responded and made an offer to refund the remaining membership monies, but wish to charge £35 (for both of us - £70) to cover the their admin fees and 'a new program at the time of joining'. I think this is unreasonable as they are the ones that have broken the contract and surely setting up a new fitness program is covered by the membership fees (they don't charge for every fitness review). Should I hang on for the full refund or are they entitled to their £70?