Upgrading and keeping UDP!

[AC Question]

OK, so I have UDP and want to upgrade my phone. Verizon is telling me that I can't keep my UDP unless I pay full retail for a new phone which is a total scam if you ask me. I have been a loyal customer for like 12 years. Well guess what, I am considering jumping ship to another carrier. I don't want the Edge plan, willing to do two year thing again. So my question, "Is there anyway possible at all to keep my UDP?" All I want to do is upgrade my phone and keep the same plan that works for me. But apparently there willing to part loyal customers!