IM NOT GONNA PAY INTEREST FOR CELL C MISTAKES

I'm really dik of cell c for charging interest on my account for they problem. I made a payment on the 25th of October 2021 my ref nr was incorrect so send them emails with the correct ref nr and call them to allocate the payment . But what did they do they didn't make the allocation right and they go debit my on my bank account twice whiles I told them I was retrench, who is gonna pay that unpaid debit fees of 230. And for that two debits they charge interest of 140 are you guys crazy I AM NOT GONNA PAY INTEREST BECAUSE ITS NOT MY FAULT I paid my account on time so cellc must make corrections on my account cause all you guys wanna say I'm sorry when I call. CORRECT YOUR WRONG DOING AND STOP THIS ROBBING OF YOUSE WHEN YOU ARE AT FAULT