Vuma is the worst

After so many complaints with my ISP and vuma I am really getting tired of the games they are playing. I am paying my ISP every month for my 100 Meg line ...while linespeed is only on average 15 to 25 Meg. Pathetic. Do this do that not fixed . Afrihost now says it's Vuma to fix i am still waiting for them to fix and there is absolutely nowhere a number where vuma can be contacted ....come fix and reply to this vuma .....