POOR TELKOM LTE SPEED AND SERVICE

So I have an LTE contract with Telkom. 40 gigabytes day and 40 Gigabytes night. Lately i have not been able to use the service and data as a result of poor internet speeds,the equivalent of a dial-up modem from the '90s. I cannot watch anything online without it buffering or a severe reduction in the video quality nor can i use it for online gaming. I have lodged numerous complaints via Facebook. Telkom has communicated to me via Facebook messenger with solutions that made things even worse. I liaised with them after each solution. The final solution was a speed test requested by Telkom which I did and submitted and they have said yet again that this is with their technical team and provided me with a reference number on the 18th of November. I have not heard back since then.

I am now looking to cancel and they state that I must now pay R1700 which I refuse as I have lost Gigabytes worth of data as a result of me being unable to utilise a service i pay for.

I Need a resolution or a cancellation that does not entail a fee as I have lost too much data as a result of poor service.