What happens to my plan if I return my phone at Costco?

[kirksucks]

I just did a 2 year upgrade (on Verizon Edge) at the Verizon kiosk at Costco. I'm still within the 14 days and I'm having a little remorse on my phone choice. But the problem is Costco doesn't have many other options for phone choices. What are my options? What happens if I just return the phone and not get a new one from costco?

Am I able to get a new phone on edge from Verizon corporate?

Am I stuck with what Costco offers?

Can I just exchange it at Verizon?