Cellc will milk u dry

I requested my contact to be canceled in beginning of February 2021 since it has ended in December 2020, I got a call from cellc that it will take 18 to 21 days to be called but I have to pay arrears for Jan & Feb for the cancelation to be successful which I did pay on the 15th Feb an amount of R855, but now cellc is busy calling and telling me that I owe them R350 for March but the contract has been canceled? Ever since this contract started I've never had a peace of mind, when I took it, I asked my contract to be "kept" at R275 which I felt I could afford that time & nothing more but still I was debited more than what I signed up for n amount of R396 throughout this contract, I have never had a fair deal from cellc, very poor customer service & consideration all they will do is milk you. I' think I'll forward this matter to Ombudsman for unfiar business conduct.