Over charged

In December 2022 Cell C debited my account days before the allocated debit order date before I got paid which obviously bounced, I then deposited on the 3rd of January as they didn’t try debiting on the debit date. I emailed the proof of payment. Then the invoice came and there was a R70 charge of a failed debit, I called to query about it and they told me it’s because the debit order didn’t go through and I asked who’s fault was it? Because the debit order set date is the 28th of each month how then do you send a debit on the day way before the set date and then charge me for that, they then requested that I send my bank statement to show that they didn’t debit on the set date which I did but nothing was rectified. Now again same thing happens. Cell C once again without any communication to say that they’ll debit my account before the set date they debited on the 26th and the debit bounced on the first of June 2023 I made a deposit and sent the proof of payment and now I’m finding out Cell C debited again on the 3rd and it bounced because I had already paid. Now today being sent another invoice with a R70 charge for a failed debit order. My question is why and the December issue wasn’t resolved and this one as well I’m really not going to be paying an extra amount for other peoples mistakes.