In my experience, The tech support or customer service representatives that you get on the phone are essentially "under orders" to make it anyones fault but thier own. Im not doubting that there is no download cap, but they'll blame rev-ed right off, even though there isn't going ot be any issue with them (I myself have downloaded just fine tow or three times since this mess has begun).
How are you going about the download? Are you jsut starting the download and walking away? As was mentioned earlier (by whom, it escapes me), it's possible that windows itself is causing it. Since microsoft believes that windows knows more about what a user wants than the user does, it often does stupid things like deciding that your not using your internet connections anymore and disconnecting them. Not your actual dial-up connection, but the connections made through IE or however your connected.
It's worth a look.
You could also try using one of those download managers...if it can be used. I dont know.
--Andy P