If you feel that your genuine grievances are being rejected both by the timeshare company and by your credit card issuing bank or finance company regulated by the Consumer Credit Act 1974, you could consider obtaining a fee quotation from a solicitor for handling the claim. Or you could refer the claim against your card issuing bank to the Banking Ombudsman (pamphlet available from 020-7404 9944).
Your home insurance policy
It is worth looking at your insurance policy to see if legal costs cover is included. A single call to your insurers should give you this information, and if you have the cover you will be informed as to how to progress your dispute with the timeshare company concerned.