Ignoring instructions to cancel contract and resolve query

In July 2020 I called Vodacom to inform them to cancel my contract because it was coming to an end the 31st of August 2020 and I did not want to renew it. The first person I spoke to convinced me to keep a sim only deal running on one of the numbers on my contract, so I accepted. I called back a few days later and informed them to cancel everything as I do not want to be bound to a contract. I spoke to several people and also sent emails and they confirmed over the phone that this was done.

On the 1st of September I was billed for a new contract. I have spoken to several people from the Customer Services and Retentions & Cancellations departments, some escalated the query, some confirmed that it will be resolved, some can't assist with my query, some call me to convince me to upgrade (after informing you numerous times that I am not interested), but no one can resolve this query.

(Please see emails sent on 16/07/2020, 20/07/2020 etc.)