Deceiving Sales Staff at Mweb

I run a business signed up for a 20Meg down & Up, however for the past 2 weeks only capable of getting if we lucky up to 4/5MEGS. So what are we paying so much monies every month. Tried calling the call centre on numerous occasions and the waiting time is ridiculous almost an hour to get through. Mweb really sucks. Can anyone recommend a better service provider, it feels like we loosing lots of money for not receiving what was promised to us.