Bad service I got from Nimble and Woolworths

I had a Woolworths account then I got retrenched the account went to bad state ,later when i could I made arrangements to settle which I did made payments into woolies account , while I was paying they sold the account to Nimble not aware of this so when I was done paying I contacted woolies for a paid up letter to my surprise the accountant was sold to Nimble . So I contacted Nimble I send proof of payments to nimble with no help so me by contacting nimble according to them I was acknowledging the depth that disrupts the time for the account to prescribe it’s been 3 years since I paid this account all this his time I’m blacklisted only now that woolies has transferred the money to nimble I’m still blacklisted I need to be CLEARED