Thames Credit / Activ Kapital

yelsel3

A while ago I posted an enquiry about Activ Kapital buying my debt to Sainsbury's Bank - what should I do etc. Followed the advice and sent the letter citing the Consumer Credit Act 1974. They have written back to say they did not purchase the actual agreement but the outstanding balance and that they have no obligation to provide me with said copy but have ordered the application form from Halifax Bank of Scotland(?). They insist they are the legal owers of the account and see no reason why their debt collection activities should be suspended and unless I am specifically denying knowledge of this debt I should pay up - to them.
I don't know what to do now as I've no hope of paying any of it at the moment because I have had to give up work due to heart problems and my husbands money is barely enough to cover our basics. Does anyone out there know what I should do now. Any advice gratefully received as this id having a bad affect on my crumbling health.