Checking Verizon ESNs

Anyone know of any good, reliable way to check Verizon ESNs? I refurbish cell phones, so often I'll have 10-20 or more ESNs that I want to check at the same time.

Typically I'll call up customer service and hit 5 for "other questions" to be forwarded directly to a representative, but I've been met with mixed results. The main problem is that there doesn't seem to be any standard protocol for checking ESN, and I think that hitting 5 just forwards me to a random department with a free representative rather than to a specific department. Generally they'll ask me for my Verizon phone number, which a bit awkward given that I don't have a Verizon account. On the occasion that they don't ask me for my number, it tends to go very smooth, with me rattling off ESNs and them checking them right away. If they do ask for my number, about 50% of the time they say they can't check ESNs for me because I am not a customer, and I just have to hang up and call back for a different person. Occasionally I'll get someone that doesn't even know how to check an ESN, and again I'll just hang up and call again.

The big problem is that I can only check a few before the representative starts to get suspicious/exasperated. Sometimes I'll say right away that I refurbish cell phones, but that often leads to them going to check with they're supervisor to see if that can check ESNs for me, which takes about 5-15 minutes. However, the biggest problem that I have is that on a couple of occasions I've been told a phone was clear, sold it, and then had the customer tell me that Verizon has it on the lost/stolen or unpaid account list when they tried to activate it. This is very awkward for me, and hurts my sales and reputation.

So, basically, I'm looking to hear from anyone else that works on Verizon phones, and what they do to check ESNs. I really think that right now my best option is to just get the cheapest pay-as-you-go account that I can, and simply transfer that account to any phone that I need to test.