I upgraded my phone two months ago and was told that the only difference in my bill would be the $10 insurance charge on my bill. Nope, it's not. I used to have the Email and Web Unlimited "feature" which is no longer available. So they gave me the 6MB offer of the same price since I had the "feature". Well, this 6MB "package" isn't the same as the "feature" and won't accept my work discount. Why not? I was forced to go to this, so why wouldn't I still get the discount. What is the difference between a "feature" and a "package"? Customer support could not tell me the difference and kept saying that my discount doesn't apply to the data "package".
If you upgraded with a subsidized phone and agreed to a new contract, you cannot keep unlimited data. Did you have a smartphone prior to the upgrade, or a basic phone? The price difference may be from a basic to smartphone plan change, because even when unlimited was grandfathered a basic phone unlimited data plan would not have carried over to a smartphone. If you still have the receipt from the upgrade, the new plan should be itemized on it. It sounds like you switched to Share Everything.