MTN Incorrect account deduction

Mtn Malmesbury and call cente service poor. MTN Deducted R4900.00 of my account instead of R390 in January 2021. December 2021 account. Since then I has been logging 10calls or more getting no response or calls getting closed with no response

Also getting a letter from MTN Malmesbury that they will refund me the money and call centre informing me that they made a mistake and will be doiing a bulk refund. This is realy poor service as I am a client years now and jow refund yet or reason for deduction.

. Please assist me with getting my money back. I am really feeling that my hands are tight in this situation.