Telkom Internet not Reliable in Consistency of Download Speeds

I have a Telkom 10GB Data Deal since October 2017. For the first month I had decent internet speed. However since December 2017 the internet speed became slower. By September 2017 the speed was so slow that I contacted Telkom and reported the problem. Telkom sent out their technicians who informed me that the problem was at the "Tower" and NOT at my Modem. The query was however resolved during October 2018 (Number ********** 6) and thereafter I had download speeds of approximately 25 Mbps. However this only lasted a short while. I therefore decided to record my Internet Speed every now and then and this is the result: Friday 9 November 2018 - 0.47 Mbps Download Speed Sat 10 November 2018 - 16.7 Mbps Download Speed Sun 11 November 2018 - 29.1 Mbps Download Speed Thursday 15 November - 0.99 Mbps Download Speed Saturday 17 November 2018- 2.67 Mbps Download Speed Monday 19 November 2018 - 21.5 Mbps Download Speed (@ 06:30) Monday 19 November 2018 - 0.33 Mbps Download Speed (@ 12:57) Monday 19 November 2018 - 0.62 Mbps Download Speed (@ 16:00) I am fed-up with this. I pay Telkom to provide a consistent service. This means resolving the fault reported was only a temporary "fix". It is evident that Telkom can't supply a consistent good quality service. I will not contact Telkom again and stay on the line for an hour before I am so lucky to get hold of someone that knows what Mbps stand for. I expect Telkom to contact me as I would like to cancel my contract with immediate effect.