Blackberry PDA access with Microsoft Exchange 2007

My company does not have a RIM server and I have been using my Blackberry with its Exchange Server flawlessly for the past two years via the usual PDA sign-up through T-Mobile. Recently they upgraded to the most recent version of Microsoft Exchange Server and all of us Blackberry users were knocked off the system. Despite my correspondence with T-Mobile and RIM, they don’t seem to care about this issue. Our IT people say that the new version of Microsoft Exchange Server supports ActiveSync only, and that’s why we were knocked off. Due to cost they have made the business decision to not support Blackberry. Is there any hope of using Blackberry with the new version of Exchange Server via the usual PDA sign-up with T-Mobile?
Thanks
RD