Cell C makes me unhappy

Cell C is the worst communications compony regarding payments. In middle 2023 I phoned the customer care line to change my payment date. The date was changed to the 7 of each month( up to this time my account was paid the 20th of each month for the services rendered the previous month) and the operator didn't tell me that now I need to pay upfront for services rendered. In November 2023 I went to a Cell C branch to talk with them to understand why am I being billed in a unknown manner and that's when I found out I'm paying advanced and changed my payment date back to the first of every month. My debit order was supposed to go of the first of January 2024 for services rendered in December 2023. It dint go of and on the 7 they billed me double my monthly fees. Debit order bounced and I had to pay them for services rendered in December 2023. Ok so now I think its sorted and the third of February my debit order goes off for January, or so I thought. The 7th of February there's another debit order that went of my account. I phoned the customer care line and they cant explain or understand their own explanations. every month I need to pay a extra charge of R70 for Cell C and R100 for bank charges because Cell C doesn't take the correct amount and on the correct day and now customer care says the 1st off March they are going to bill me doubled for services rendered in February and March bust I'm supposed to pay in arrears for each month.