Can't actually see the difference

I got a surprise today when I switched my PC on, it turns out that the ADSL speed has been upgraded by our switched on monopolistic ISP. Trouble is that there is absolutely no difference in the speed of pages/downloads/connections whatsoever. Now I do know that there is a contention rate of 50:1 on the local exchange and that the download speed relies on the upload speed of the machine that I'm connecting to, but to see absolutely no change whatsoever is still a little bit puzzling. After doing a little research I've found that while the actual connection speed is now 3 times the previous amount, ISP's can still throttle the amount of traffic for certain services and types of connection. So while they are still claiming to offer speeds of up to 8Mbps, they can (and do) only let you have access to a certain percentage of these. What is the point of this? The only one that I can think of is that they want to pay lip service to the fact that they can offer the same service that companies (including themselves under a different name) in the UK have available, but don't actually have to provide the same end result. What can we do about this? At the moment next to sod all if you've not been with them for the requisite amount of time to change your contract and move to an alternative provider (that they are supplying wholesale to, so it probably makes no odds anyway)