Data cut off despite money debited

I have a data contract with MTN for R299. They successfully debited my account on the 25 of April the amount of R317.99 without my consent and beside that they claimed cut my data on the 11th of May to date when I queried I was told that its due to unpayment. I spoke to Sthembile Hlangu who was so RUDE and left me on a call for 10 minutes. I need this issue to be resolved as I sent bank statement reflecting debit from MTN even my bank confirmed that it went through. I am not happy with their service. Even their staff especially Sthembile are *********** and doesn't deserve this job.