TFG Calls for magazines balance owed which magazines I have never received

So I had an account with them for over a year after which I decided to close in December 2019. This was because I was always paying for magazines that were never delivered. It was more than 5 magazines.

In December after clearing all the money owed to them, the account was closed. I was shocked to receive a statement in January 2020 from them stating that I was owing. They even went ahead to call.

I decided to go to the store and make payment but on reaching the store, we were told that the account was closed and we didn't owe anything. It's now May and they keep calling saying I owe about R400

I have been going to the store and the store doesn't pick up any balance owed to TFG. I am tired of their calls since even the magazines they say I have to pay for, I didn't receive any from them. They even advised that I tell the cashiers in the store to call them which was done but they keep on bugging me.

I think this is a problem on their side. I was and am still willing to pay the 400 which they say I owe but am tired of making back to back visits to their stores and I will not give them my account details for debit orders. Never. TFG sort yourselves out please