Bought VZW iPhone X w/ VZW carrier billing, put ATT sim card in before VZW, now locked to ATT

So just like the title states, I have an odd problem that nobody can seem to solve. I have called both carriers to no avail, completed the unlock form (nothing yet), and am at my wits end as far as knowing what to do next.

I bought this device under a carrier financing agreement through Verizon, but the sim wasn't provisioned yet. I slapped my ATT sim card in (no device payment plan/contract) to finish out the billing cycle and port my number out. I put my VZW sim back in to initiate that process only to get the Sim Card Not Supported error when trying to activate. 

What does a person need to do to resolve this? None of the CS reps know what to do short of submitting the unlock request form.