Cell C Contract cancellation nightmare.

Cell c hasn't cancelled my contract even after i have called to tell them i am cancelling, now they are busy debiting money in my account but my contract has ended. this is ***** my contact ended in June 2020 after fully paying for 24 months, now cancelling with them is a nightmare, when you call the number 084 143 it cuts you and no one picks up. when my contract was about to end in June i called cell c to cancel my contract but apparently it wasn't cancelled because i'm still billed by cell c. can you please cancel my contract and not force us to pay for services we no longer using or need.