Unhappy customer

I am writing to formally express my dissatisfaction with the service provided by Mweb regarding my MTN LTE 15Mbps uncapped subscription. At the time of sign-up, I was quoted a fixed monthly rate of R419; however, the actual deductions from my account have fluctuated inconsistently each month. Had I been informed of these potential increases during the application process, I would not have entered into this agreement. Furthermore, I submitted a formal cancellation request to your complaints department a week ago and have yet to receive a response. Please process the immediate termination of my subscription and confirm receipt of this request.