I have been a customer with MTN since cell phones came out

I have been a customer with MTN since cell phones came out. I have a query since October 2023, I have visited the Eastgate branch, I have called the customer service-123, sent emails to no avail. I received 35 sms's today with OTP's. I was on the line for over an hour with MTN *****, and they said I must call International Call Group. I called ***, as I got this number from an that called me on the 03/07/2024. When I called this number the gentleman said he could not help me. He said this company is called Mondo. I am soooo frustrated. Can someone from MTN, preferably a manager call me urgently