Woolworth

Before 2016 I had an account with Woolworths which was hand over to the attorneys in 2016 after I lost my job in 2015.I settled the account with the attorneys in October 2016 but did not obtain pay up letter.Two years letter I received communication with the same attorney regards the same woolworths account and I told them I settled the account with them in 2016 but they are denying the fact that my account was with them in 2016,I tried liaising with Woolworth on end but they are not helping me in any way