They never closed my account

I paid off my account on the 18th of August 2018 and instructed the cashier to close my account. Around March this year I went to old mutual to apply for a loan and was told that I have not been paying my exact account. I went to exact to get more information and was told that my account was not closed and the account was owing due to magazines they have been sending me (funny coz I have never received not even one). I asked them to sort it out but instead they handed me over. I have gone to the Pietermaritzburg branch to sort this out but till today I keep getting calls from the company they handed me over to and my credit status has been tarnished. I am very disappointed with exact and I wish they can sort out this error.