Jet store paid up letter.

I had an account at jet stores I then app**** for debt counselling and later on finished paying jet but did not get a paid up letter and this happened 5 years ago, I then collected all my paid up letters but now I'm struggling with one from jet stores, they said they Cannot issue me with a paid up letter because it was sold to TFG and they do not have my details on the system since it was sold to TFG, I tried to contact nimble group they cannot find my information and now debt counsellors cannot clear my name without a paid up later from jet.