I experienced the exact same thing after I changed my 10meg adsl to home uncapped. Their website t&c's say u will be throttled after 150gig usage but guess what, I got throttled to 1mbps after 80gig usage. Between 4 Afrihost staff I got 5 different answers; from a system error or you used 50gig in one week thats why we throttle you or no you are mistaken Afrihost is not throtteling at all. Needless to say I moved back to 200gig capped and can't wait for my ftth to be activated by another isp. Afrihost is no good.
With Cool Ideas, I no longer know what my consumption is. I do not download the internet. I have never been a big consumer. It is just that uncapped is happiness on CISP.