If you want to back out, what about Freedom2Surf? Still 8Mbits, but a bit cheaper than Wanadon't at £20 and the allowance is more generous at 10GB. More to the point, the included features are more generous as well, and there is no contract!
The reliability has been perfect for all of the last 18 months. The phone support has gone downhill a little bit, with longer waiting times, but that's it.
There are other similar options out there.