Home Choice poor service

I had an account with Homechoice for a few years. I was retrenched, and phone them to for the outstanding balance. I settled the account last year October, and asked them to close the account. After 3months they phone me, and told me there is an outstanding amount of R360. They never closed the account. Now they have handed me over I refuse to pay the outstanding amount because they didn't closed the account. I have even send a mail to there customer care and they didn't even respond.