Worst experience I have ever had with an ISP

I have the 5G premium package and I get a 5mbit/s speed after 6 pm if I am lucky. The technicians were here, lifted the router about 1 meter up and told me: "it is already in the best spot signal wise and the problem is congestion" So I am paying R1000 per month for a service that I can get for R200 p/m and there seems to be no resolution in sight. Just don't even bother with rain, get a 4G package from someone else rather, even that is much better than their 5G "premium" package. Please note that this has been going on for months now.