PDA SMS 2000 Allowance incompatible with device?

[Quick]

Back around 1999/2000 when I got my Treo 700p VZW had an unadvertised feature (PDA SMS 2000 Allowance $0). It was so people could do a kluge to sort of simulate "push" email. In any event I've carried that feature as a grandfathered feature through my Droid 2.

While ordering a Droid 4 online, the website said that feature would be dropped so I called. I told the rep I absolutely wanted to keep that feature. He checked and said it wouldn't be a problem. That I should just enter anything plan related to keep the website happy to order the phone. He said any plan changes entered there were not applied until the phone is activated and just to be sure to call once I had the phone in hand and before activating it. He made a notation on the account to this effect.

So I have the phone. I called, explained the situation and I get "That feature is incompatible with 4G phones". I tried to explain it was a billing issue/restriction with no joy so I tried VZW data services (they're usually a lot better on these things and not just following the customer support menu text). We went around a bit on how it isn't a technical issue but a billing one. He finally asks his supervisor what can be done and she relays that "it was a promotion and the conditions were that nothing on the plan changes and going from a 3G to a 4G makes it an incompatible feature"... ummm...  Is there any chance of my getting to someone that can override this in the system?

bonus question : (I don't think this is an issue but I'm curious) I also have another feature which is to be dropped. General IP Nat Address. What is that? and why would it be dropped going from 3G to 4G?