Unsatisfactory service received from Vodacom

As I have wrote recently that despite sending numerous e-mail to Vodacom to cancel my contract and I have not been receiving replies. I have received a call from Vodacom during the course of this week and they advised that my matter was under investigation. This morning I got an e-mail from Mondo Group advising that the result of the investigation has been proven to be invalid. I called and spoke to a Consultant of Mondo group who advised me that I spoke to agent in accepting the data change plan which I do not dispute but no where in the conversation had the Agent advised me that I would be upgrading had I known I would not have accepted same. I feel that this is very unfair on me because I had sent Vodacom numerous e-mails timeously and also advised on 1st July 2024 that I do not accept the rewards that I was offered as I am putting in my cancellation notice and I also contacted vodacom regarding my cancellation and they only sent an sms. Vodacom neither did I receive a call from Vodacom Cancellation Department at the time and regarding the e-mails I only received a reference number to my knowledge Vodacom accepted my e-mails and I am in this problem because of Vodacom. AS ADVISED I HAVE STATED IN MY E-MAILS TO VODACOM ON 1ST JULY THAT 2024 I AM NOT ACCEPTING THE REWARDS WHICH WAS OFFERED TO ME AS I AM CANCELLING MY CONTRACT . SO NOW MY CONTRACT HAS BEEN EXTENDED TO 2026 WHICH I AM NOT PREPARED TO PAY .