I'll bet it isn't completely impossible. You just need to find the right person. Let me give you an example. Just bear with me to the end.
Everyone and their mother at Verizon swears up and down that it is impossible for a new customer to get unlimited data. It's no longer in the system so it can't be done. This is untrue, although, things may have changed since I last checked (about a year ago).
A new customer CAN get unlimited data if they take over a line. You would have to contact the Assumption of Liability Department at (888) 832-4540. Now, I'm not saying to do this in your case. The only reason I bring it up is because it proves that a new customer can come to Verizon, be entered into the system, and CAN get unlimited data even though it is no longer offered. You also get the ability to either port over an existing number, or get a new one. That however is a different process unrelated to the assumption of liability.
Again, I'm not saying this will fix your problem. It's merely pointing out that things can be done that everyone says can't.
How did I come across this info? I got married and my wife's family had a better plan than me. I was brought in. Later, my company offered a 25% discount through them for Verizon. This was after Verizon got rid of unlimited data. The process was laid out so that I would take over my line under my name. I would be made head of the account and everyone would be brought in under me. All numbers would be ported, plans would be kept the same (even though the options no longer existed), and I would receive a 25% discount on my bill.
Nothing is impossible if you talk to the right person in the right department.