CELL C IS PATHETIC

I am trying to cancel my deceased Mother's Cell C account. I have emailed them on 5th July 2022 and got a read receipt and again on 20th July 2022, both receiving read receipts. They are still trying to withdraw the monthly subscriptions from her bank account but have not got the decency to respond to my mails like I have requested, as I need to know the way forward to cancel the account. File is at legal department but they are not doing anything about it, despite having all my contact details