Cell C needs to stop ********** debit orders from my account and refund my money

Took up 3 contract with Cell C in 2016 and it ended in 2018. I called in to cancel 2 contracts. To my amazement i found out that Cell C was still charging me for contract that ended in 2018.

I called in on the 26th of October 2020 to end the ********** debit order. I was assured it was rectified but am surprised that i was again debited today. Please i now want refunds of all the debit orders for the number ***) in question as i had ended it way back in 2018.