Why won't verizon let me switch phones?

Alright, so I had the LG voyager. But something happened and the buttons on the front fell off. So I got a new phone, which was the pantech jest. I'm on my third replacement of that phone. So I thought I'd switch back to my voyager. I called *228 to activate it, and it said "we are unable to program your phone." So what should I do?