Terrible customer service and overall experience

We've received terrible service from afrihost in stellenbosch. We increased our Internet speed from 20mb to 50mb and after paying for 50mb the speed wasn't increased, and we are still receiving 20mb. After contacting them numerous times, they keep blameshifting vumatel, and sending out technicians to work on the line, while the issue is with afrihost not making any changes on their side.