Okay, here's the deal. The warranty has never been transferable, even before Frank took over. Anybody who told you that was uninformed or lying. The warranty is posted on www.vanguardpaintball.com
in the form that it has been in since it was created. That's part of the reason it's a good idea to buy new. This is a common practice amongst all manufacturers and is no unique to Vanguard.
In regards to "Vanguard lost my marker." Yes, that happened a few time around the time the company was changing hands. Each if them has been resolved though probably not to the satisfaction of the customer which is very disappointing in my mind. However, that has not happened since the change has finalized.
I'm sorry you feel it's unfair for you to pay, but it's realistic in the industry as well as most others that a second hand product is not covered.
I'd send it in and get it working so you can enjoy it.