Disgusted with Cell C - costing me more money

Good day

Please assist as I am extremely upset, I called the customer service of Cell C in January to change my debt order date to the last day of the month as I have started a new job. I was after taking the time to confirm this will be done correctly I was still debited this morning so now I have to pay the bank charge for not having sufficient funds in my account yet I informed Cell C to change the debit date.

Your urgent assistance is appreciated and I want Cell C to over the charge of bank chargers