Line speed and issues

Good day

I have spoke to your your call centre over the last 2 weeks over issues with not receiving 20/20 line speed for download and upload. I have purchased a new network cable and a new network card. The wireless in my home is broadcasting 100% perfectly with no issues and the speed that is required. But the speeds for the direct cable connection are not 20/20 and nowhere near. I have also upgraded the firmware of the tplink router succesfully and rebooted to no success.

I have sent numerous emails as requested by the techies on the phone for the speedtests which were done for reference and no response. I need urgent assistance to resolve this issue. I was told it would be escalated and no assistance to date. I cannot keep paying for a service I am not receiving