Duplicate and refuse to remove and update

I've struggling with nimble group and cellc for 2 years now cellc issued me a paid up letter and nimble group doesn't want to accept it and remove me of their data base they instead keep on telling me why cellc issued me a paid up letter I've provided them with paid up letter and proof of payment and still they don't accept it after they told me before I made payment that cellc has retracted my account !!I need assistance because on my credit report both accounts reflect with the same account number but cellc reflects as closed and nimble group reflects as in arreas please assist me as soon as possible