Angry

I took out a contract in 2020 with Cell C, on the 22 July 2021 I settled my account and asked if they could close is they agreed, I emailed the proof of payment and I was promised that a letter of confirmation will be sent to me up to this date I haven't received. January 2022 they started taking money from account I have been reversing the debit order each time they deduct. I have tried getting touch with Cell C with no success this morning I'm told I need to pay an amount of R700 because my number is now on prepaid I stopped using that number the moment I settled my account