CellC Incompetence! Still Paying for a cancelled contract

Extremely unhappy with Cellc! I cancelled a contract with them in March 2023 (which expired in May 2023) and due to their incompetence I am still being debited for this up till end June 2023 and each month the debit increases. I have phoned numerous times and Tsepho, one of the floor managers, assured me they will listen to the recordings and rectify the matter. They keep telling me someone will contact me but no one does. I am sick and tired of struggling with them and they do not do what they say. I am certainly taking this matter further with the ombudsman and I will be cancelling my other contract with them as well and move to Vodacom. I have been a client of theirs for 15 years and this is the treatment I get.