I think you have a dodgey line and you need to log a fault so that it starts syncing at 10mb.Afrihost themselves. I must have it on a ticket somewhere or an email. Also the contractor that installed the line said the same thing.
But hey, I'll have to go look for the proof before anything would be done about it.
The problem isnt just that. I do test regularly with speedtest .net and googles speed test. I have yet to see that rev counter go over 5Mbps to be honest. It's a good day when it's around 3Mbps which is average half a day, the rest of the times it fluctuates from 1-5Mbps.