Cancellation of contract

Since the May 2021, we have requested for an account to be closed and changes of banking details to be moved to my mothers bank account. We went into the Witbank branch (Highveld mall) to update this, this was done in store twice and the salesman said that we need to make payment for this account to be closed, payment was made and nothing was done from Cell C. every month it is a battle with them to get this changed and moved over. Emails was send with all relevent documents to ***. no communication recieved from them and yet this month it is the same story over. documents were send for cancellation etc. This company must wake up and start doing there work. I want a manager to sort this issue out as it seems like all employees are ***********.