Debit orders

Hi I apply for mtn contract in july 2021 . My monthly installment is 319 . From August they deducted 319 till November but on the 4th of December they deduct R1791.when go to the branch to query they tell me I over spend which was lie . And they never help me and never return my money .and I decide not to use their sim card anymore. On 5th of January 2022 they deduct the same amount R1791 when i call them they say i over spend i never use mtn sim card their monthly data and min is still the and their telling me i over spend. Now they send me an sms that am owing them R1800 . I went to the store at Brooklyn and I never get help . I call head office and the lady who help me she agree that what they did is wrong and she promise to request refund on my behalf. From that day till today I never hear anything from MTn . All I see is a opening and closing of my query . And I really don't want my name under bad record. Ref *** *** *** My cell ***