It sure sounds like you have 1 phase 3 wire coming from a 4 wire Wye system. The readings of voltage to ground on all 3 lines removes some doubt that the system is of another configuration [described later].
Line B is common to either A or C [there's a voltage being read between these lines] and each line has voltage to ground, so this is really looking to me like someone, somehow and somewhere has connected the service feeders for line A and line C to only the "X1" or "X3" termination point from the Wye bank.
Also, as someone has mentioned, the system may be an Open Wye, which explains the 215 VAC from L-L [that should be somewhat normal on a lightly loaded or unloaded Wye setup, especially when the Transformer Impedance is a high percentage - like 5.0% or more], and for some reason, someone installed feeders to "Appear" like a 3 phase setup - why this would be done is anyone's guess.
Don't really see the benifits of installing an Open Wye system in a commercial enviroment, but who the heck knows?
If there's some way you could trace things back - along with verify if the Transformer [or bank of Transformers] is setup as a 4 wire Wye system, you would stumble across the above mentioned mistake in connections.
If you were using a DVM for testing, the 215 VAC L-L would be very common. You would maybe get higher L-G readings, but not necessarily.
Question: Are you measuring Line To Ground voltage between one Ungrounded Conductor and the Grounded Conductor, or to the Grounded Equipment [EGC]?
This doesn't change anything, I am just curious to the L-G voltage readings.
Anyhow, if the situation had L-L voltage equally between A-B, B-C and A-C, but L-G voltage was not "Typical", that would be a clue towards some type of Delta system.
Higher than expected L-G voltage readings would be a result of an ungrounded Delta.
One Line [such as "B"] having zero volts to ground, and the other two having the same voltage to ground as is read L-L would be the results of a corner grounded Delta.
All three Lines having voltage to ground, but one Line is quite higher than the other two read out would be the results of a Delta 3 wire with the center tap of one coil grounded at the Transformer.
Once again, this stuff is only "FYI", not crucial to your situation.
Hope you get the problem taken care of without too many headaches!