Monitor Service Tags

I'm posting here because I have been unable to contact Dell to get answers.

We have recently received three 2900 servers, 3 MD1000 arrays, various supporting peripherals (switches etc), and 4 monitors. Before they are deployed, we need to log serial numbers, verify warranty registrations, and so forth. Apparently, the monitors don't have a service tag. Without a service tag Dell won't let us register it, check for updates, or even talk to anyone.

A third party provides the equipment. Until recently, the equipment has always been from another manufacturer.

Since all the equipment is new, I'm concerned about Dell support. Is this the type of support we can expect in the future?

What can we do about the monitors and the service tag issue?