Pay R806.01 for a R699 service - *******!

I have come to my wits' end. I have been charged R806.01 for my 50mbps line since 1 April 2021 but I was told the cost is R699. It was not a promotion and even now the Fibe Line is advertised to my address as R699, but I was charged R806.01 every month. I open SRs and they just get closed. Even the latest SR *** in which I also notify them that I am now cancelling my Fibre and want a refund rather than credit and correction of the charges was simply closed. Vodacom support structure is incredibly *********** and there is no way to escalate to anyone who can help you.