Hi Patrick - it's a not uncommon issue raised on forums inc
Money Saving Expert where a debt/charge has been passed on to another creditor.
From a registration perspective if it's a legal charge then we need a form DS1 executed by the creditor/lender as appropriate. And if that is someone other than the one on the register we also need proof of their legal authority to discharge the registered charge.
You will need to continue to follow the trail so to speak to identify who can legally discharge the charge and provide you with the required form and supporting evidence
If you are trying to secure equity release then it might also be worth speaking to your legal/financial adviser to seek their insight and help also