Bad service /debit order chsnged

I actually don't know what to do with mtn anymore. Im sick of not getting assistance. Mtn decided to change my debit order date from the last day of the month to the 12 of each month. Been calling mtn every month since june but still no change.

I called last timw requested for a manager but then the call was dropped. Im sooooo unhappy with ur service.

Im sooo disappointed with Mtn on how they do things. I was told its a technical error bt why Can't it be Fixed??????? What kind of service is this?