MTN Payment reversal required

I have called VVM who apparently was handling my MTN account which fell into arrears a few years ago when I lost my job. However, I have steadily made payments since last year and manage to settle my account last week. I received an sms indicating that I am to make the final payment of R514 on my MTN account. I then made an EFT payment of R520 on 25 September 2019, I have send MTN and VVM the proof of payment. I did not realize that I still had an active MTN scheduled payment on my online banking. This payment then went off via debit order on Friday morning, 27 September, I have send the proof of payment for this as well. When I called, I was told by one of VVM consultant's that they could not find me on the system. I then tried my identity number but still nothing happened. They then said that the account is back with MTN and I have to make contact directly with MTN. I have done this numerous times. My bank FNB says that they are not allowed to reverse a public entity debit, MTN has to do this. May I please request that 1) the appropriate amount of R510 be reversed back to me asap and 2) that I receive a letter that the account has been paid up. Both these service providers are quick and persistent when they are wanting you to pay etc but now that the roles are reversed there is no answer or accountability. I really hope that someone will be able to assist me please.