MTN debiting wrong account after multiple calls to 135 to have it changed

Changed my banking details in January with MTN and they kept deducting the wrong account every month. Have phone the call center on multiple times to have this sorted and nothing is happening. My service keeps getting suspended. A debit order than suddenly ran on the 14 of April (at least of the right account). Have asked managers to phone me back multiple times have not happened. Sent a customer care mail on the 7th of April no communication back.

Tired of having to explain the same story every month to different people at MTN.

Please contact me asap to have my account fixed.