Poor billing process

Last month I received an SMS stating my payment has not been received, this happened shortly after Telkom debited my account. I ignored the SMS as certainly it was sent in error but to my surprise a few days later I received an invoice billing me for two months as well as a unpaid charge. How on earth do you debit someone’s account and then not have any record of it! The same thing happened to my colleague almost a year ago and only after several months had passed and numerous calls was the issue resolved. I refuse to call your call center as I am fully aware of the poor service. I need someone senior to call me