ping is too high for any kind of online gaming. almost half a second of lag

Ok, I'm curious to know if anyone has had a similar experience as I have:

I signed up with iZZi, and during the first week, the speed was fantastic.  But after the first week, my speed started dropping, to the point where it is now officially slower than what I used to get from Streamyx.

And I'm not even talking about torrents.  I'm just trying to surf the web and play Scrabulous on Facebook.  And I'm sitting here, twiddling my thumbs, waiting for the damned pages to load.

iZZi support has been pretty lousy.  I took screenshots of my bandwidth speed tests and sent it to them nearly a month ago.  Called a few times since then to follow-up, but they just keep saying that they've notified their tech people and they'll get back to me soon.

I've got 100% signal strength, and I got really good speed during my first week of subscription, so I doubt it's an issue with my location, the coverage area, or any of my network settings.  Nothing has changed.

I never thought I'd encounter a broadband provider crappy enough to make me consider going back to Streamyx, but here I am.

Comments?  Suggestions?