Disgruntled customer

Early in March this year I paid up my Edgars account which was at R1200, there was a small balance of R114, when I paid that large sum, I called in and asked for them to close my account, they assured me that this was going to happen. Today I receive a call to say i am outstanding more than R600 and need to pay in order to settle this account. This is unacceptable as I assumed my account was already closed. Would I now need to pay the R600 + to get this account closed again? Pathetic service and never again will I visit an Edgars store.