Is it possible to sell a debt once payments have been made on it?

I have a debt which was originally in norway, which I asked to be sent to a collection agency in Canada. They sent it to the states. I have made a couple of payments on it but it has been a gong show each time, and I figure it would be easier if the collector was in Canada. They told me the case 'is in the states'. Can't find anything about this sort of situation with google, so please HELP. thanks:)