you need to post you stats so mods can see your current connection - last stats were in February.
did you get an email from BT regarding the exchange upgrade and that your conenction is going to be upgraded?
did you get an email from BT about exchange upgrade?
It should be done eventually, but don't count on it. It takes time to migrate everybody across from the old DSLAMs to the new ones, so it doesn't all happen overnight.
If there is Infinity available in your area, then they may just be waiting until you get sufficiently fed up with the slow speeds that you decide to upgrade to Infinity. BT seem very reluctant to do anything to improve ADSL speeds if you could switch to Infinity instead.
In my case, the only way I could get anything done was to contact the mods here (thanks, mods!).
what has chnaged since you posted here in February?
by the exchange has changed do you mean you are on a different exchange or the exchange has been upgraded since february?
just need to wait on mods contacting you - you may need to agree a new 12 month contract if you get upgraded now instead of waiting for the rollout
If you were promised the higher speed, and are in contract, then you should be higher up the queue.
Last time I was upgraded (about 3 years ago, before I moved house), it took several weeks. But I was out of contract, which means I would have been at the back of the queue.