Double debit

I usually get monthly statement from cell c for my second contract and the debit order is on the 25th of every month. The beginning of August 2022 I received the statement reflecting that I won't be paying anything so basically it was a zero balance statement. Beginning of September 2022 I get the statement for the month stating that the normal installment of R298.99 will go off my account. Fast forward debit order date double the amount was taken. I phoned to find out and the lady I spoke to said she will send me case number via Sms and that somebody will contact me on Wednesday and to date I am still waiting.