Debit on expired account.

My contract with Telkom ended MAY 2020. I had sent letter/ Email prior to expiry to notify them that I will not be renewing my contract and it should be cancelled. June, July, August and all other months my account was still debited thou my contract came to the end and I had officially cancelled it. Numerous calls to the consultants were not fruitful as my account was being debited every months. In December I emailed Celet regarding the same issue and still no response until today. My contract was R99 but I was debited R 818, R 958 and I had to dispute the debit orders at the bank. Telkom must make sure that my account is cancelled and closed and I did sent the cancellation letter on time and someone decided not to do their job. This looks like a **** as someone *****s our monies. I'm hoping that someone will get to the bottom of this and get this query resolved.