Suspension of account

As usual pathetic service from Mtn My account was double billed in August last year .I complained to Mtn about it and was told they could do nothing about the matter, and that I should take it up with my bank. Which I did and had the full amount credited.i then paid what was owing at my local Mtn store. All good! Two months later exactly the same thing.Follow same procedure but this time decided to move over to paying account cash every month to avoid hassel as clearly there debiting system is useless. Now my phone gets suspended by MtN , they claim I never paid my bill in August 2020 and I'm a month in arrears.

Give me strength!