It's worth noting as well that uncapping won't neccessarily give you the bandwidth you say you should be getting. If the area you live in is oversubscribed, contention is the likely problem. DOCSIS cable modems have a shared bandwidth of 33Mbps downstream and 10Mbps upstream per channel. This means that it could only support 16 customers with a 2000/384K service before contention comes into play. It would be unfeasible to have a CMTS for every 16 customers due to costs, so all cable companies will have between 20 and 100 times this number of subscribers per CMTS.

The only real solution is to either change ISP/cable company, or hope they see the frustration they're causing their customers with their greed, and resegment their network to reduce contention.