Very bad Customer support for fault reporting

We have Cell C fibre installed for a year and suddenly at the anniversary of the installation, our speed dropped down .92 Mbps download and .72Mbps upload. Our service is 20 down and 10 up. I have been struggling to get someone sort out the speed but no success. All I get told is to reset the router. Then they tell me to connect the router directly to prove that it is not the wifi router that is faulty (my workstation is very far from the router and my laptop does not have a network connection. To plug the cable into my workstation, means I have to set up the connection, something I don't know how to do. It does not give me an IP address and therefore no connection. Then I must send them three screenshots of the speed. My reasoning here is that if my speed is so slow (incredibly) my line is obviously faulty. There is no way I get to speak to a technician because I must first send them that information before they will communicate with me. That took me three days and numerous emails and telephone calls to establish. This is terrible after sales service. Open Serve is my service provider and Cell C is the ISP. I am still trying to get my computer set up to get a direct link, therefore, I will not get help. I dont even have a fault report number yet.