Over charged

In October 2025 I changed banking details which I communicated with cell c. Told them that the old account is closed and no longer active and was willing to give my account number at the time, was told that unfortunately the account has to be 3 months old before they can debit. I asked (to avoid extra fees/ unsuccessful debit order charge) was told i can pay at Cell C store/ their Nedbank account or pay using easy pay number. October and November I made a payments using easy pay number, in Oct i paid on the 24th, Nov 25 and December 23. To my surprise i got my Jan statement and there's a debit order failed fee of R70 on all my 3 account which was never there oct and nov. I refuse to pay that extra R70 charged because iI communicated with the changes, why try to debit on the account that is not active. This is day light ******* and I refuse to pay R70 extra. i need cell c to send me amended statement with R70 not reflecting on all my accounts.