Telkom wasting my resources

Every night, without fail, my internet connection slows down after 8pm. I can't do anything concerning the internet; it takes a simple website almost 10 minutes to load and sometimes the connection will even time out before it manages to load. I have rebooted the router and all of my devices to no avail. I have called the Call Centre as soon as it happens and have waited on the line until it drops because no one bothers to answer. I have also gone onto the website to try and get help from their Chat Service but the website keeps reloading as I press send and I am forced to retype the message, over and over again, which only leads to further frustration.

I am absolutely tired of this as there is a problem every few weeks but Telkom still manages to take their money every month, regardless of whether or not service was delivered. On top of that, they make it an impossible process to cancel the line and still try to shove more products down your throat with their cold calling agents.