Overcharging, no customer support, no resolutions

Incorrect billing where I have been charged for an "upgrade" to my line which was never upgraded. I was being charged R849 for a 20/20mbps line. To justify the overcharging I was then advised that I was receiving 50/50mbps this despite all invoicing indicating the 20/20 service I subscribed for. Then I see that the 50/50 services is only R489.00 I requested that I be billed the lesser fee for this 50/50 service/ first month I get billed the lower fee R436.13, the second month I get billed a fee of R847.71. I query this and I am told I have been charged an "upgrade" fee. To be clear I was receiving a 50/50 line and was "upgrade" to a 50/50 line. I have requested a refund as their has been no upgrade (Ticket SST241296 was closed without any action from this organization). I have now been debited an amount of R901.00 when the invoiced amount is R489.00. This organization and its billing department is absolutely clueless and there is no skilled customer support that can actually assist. The WhatsApp support is dismissal and one can never call in as the line never works.