I suggest crying, giving up all hope, and making the side you've been playing with your new main or buying a main on here. 
Once they freeze you for selling/buying neopoints, you aren't going to get your account back. I have been there.
I'm so sorry you've been in my shoes! It happened to me before, way back when Neopets wasn't owned by Viacom... I didn't even bother trying to fight with that one.
I was absolutely speechless when I logged in to see that I was iced with this last main, though.

I called Viacom and worked my way up to a manager of something to do with Nickelodeon and she caved in and gave me the number for Nickelodeon Virtual Worlds. I was on the verge of wanting to call and
nicely demand my account back since I actually didn't buy or sell any neopoints.
I could careless about the neopoints to be quite honest. I miss my pets, my lab ray, and the thousands of items I accumulated over the years.
But... alas...

I think I may be coming to terms... I just wish there was a way to get it back