Supersonic fibre

This is the worst service I have been experiencing. I have only been receiving a 10/10 internet feed. I would like to add that I am paying for a 20/20 line which is almost a R200 difference. I have been sending them proof of this everyday. This has not been resolved. They are obviously billing me for the 20/20 line although this is not the service that I have been receiving at all. I have asked for a report showing how long I have not been receiving what I am paying for this I also have not received at all. I am outraged they want me to pay in full for a service that they have obviously not been supplying nor are they planning on rectifying the matter. This is absolute theft