Poor service to cancel contract

I've been trying fo months to close an old expired data contract that i don't use... Phoning did not produce results, e-mailing them got me nowhere... So I went to the Bloem Waterfront store on 22 Feb 2021. They assured me that they have cancelled the contract, printed out the confirmation with a reference number... And this month the payment again went off again, but double!!! How on earth do I get this blooming contract stopped for good and my money returned???? Phoning them to waste time listening to music and then they have excuses why they can't assist is just not acceptable. Can someone in MTN PLEASE fix this?!