Debt I had paid for but still existing

Last year November I visited a tfg store with an aim to get settlement aim to pay out the amount I have to pay in order to close my Markham account that came with the 121 data for my mtn number, was given a settlement fee of R5400 of which I paid off on the 4th of November and requested to close it, day of settling. I was advised of a insurance I have for a phone which I then requested that it be canceled too because am looking to cut down on my debts, went to do a sim swap with the exact in Durban and I asked why is my is my closed account keeps billing because I paid out tfg in full and never got a clear explanation regarding that. 4 months down the line am sent a statement saying am owing R484 which is by 121 for the data am supposingly getting every month since November but my sim card of ********** 807 is no longer active or on the mtn network and inactive.

When a client request a settlement to pay and close account, shouldn't they be advised of what they owing all together as how the monthly installment was sent to them? Right now I have a debt over my head that I wasn't advised too as how on earth was the fee for 121 not included on the settlement fee that was given too me to pay off?

I have a debt and an inactive number thanks to Markham and their staff that did not do their jobs accordingly. I can be reached on ********** 013