Willy, had the same issue. One thing you need to check. Is the cooling plate in the fridge icing up over it's entire length ? If Yes, might be salvaable. If No, then its most likely a gassing issue and unfortunately unless you have mates in the refrig industry, you've just picked up a lovely freezer for the missus (sell it this way, the rolling pin won't hurt as much...honest) and a fermentation fridge for you. If it's got some age to it, no one will want to touch it EPA laws and that crap. Also no gassing points, at least on mine.
But there is a chance. Mine was running fairly often or so I thought, cooling plate was icing, but 7deg at max was a little disappointing. Replaced the thermostat (not a huge job) and now I get 2-3deg with the dial wound back .
Wish you luck.