Mweb non-existing service

My wife is using Mweb as her internet service provider at home. She pays for an 10mb line and unlimited cap, which cost her R919 per month. It is now for a couple of months that she reported the speed is very slow (0.5mbs to 4mbs). Still they are ignoring her request to get the speed sorted. Mweb service is like non-existing. If I pay for a 10mb line - I want 10mb available, which means I pay for a service that I do not receive.