Very very bad service yo the consumer

I have been struggling with thesetwo companies for a while now. I have a 4mbps line with mweb as my service provider and line rental from telkom. Mu internet speed runs lower than 1mbps. How is this possible. When i phone them they say that nothing is wrong on either of their sides. I went and bought a new modem and new wiring to see if the problem wasn't on my side but still same story. Every month i just have to shut up and pay up for this pathetic service. Can u please help me with this issue.