Please do your job correct ! unapproved debit order

I have phoned MTN as my contract was scheduled for a review I have decided to change to pay as you go basically cancelling my contract until the Samsung S23 arrives as there isn't a handset available on the market that i am interested in , the retentions department did tell me because Iam a loyal customer for over 10 years they want to keep me onboard and I decided to talked the package Mega Gigs XS until they have the handset available that is R79pm, yesterday my debit order deducted R1163.12 I did phone the call centre at 10pm they said they can see the problem so definitely someone did not do their job , so they insisted i must phone today 02/02/2023 , this is absolutely pathetic customer service and I will follow up as I want my recordings as proof , i will go to the bank and reverse the debit order and keep the recordings as proof and provide it to my legal representative as this is unnecessary drama as i must take time off from work to resolve this issue , absolutely unacceptable , MTN must phone me and go through my contracts /profiles iam frustrated I cant believe in 2023 this is the customer service Please sort this out Today , my money is hard earned you gave you the authority to continue with my old contract how can i still be paying full amount for handsets when the contract has expired and have been renewed for a different contract What the hell!? I need all my recordings