I see what yall are saying.

To me makes sense how they are saying it.

Your CALL will be answered in the order IT was received.

Same subject makes sense to me, but I promise I know jack shit about English Grammar.

But I think since the subject of the sentence is your call, doesnt have to insinuate that there is a number of calls.

I seem to recall hearing a message indicating "there are N calls ahead of you, the estimated waiting time is N minutes."

This would be better than the ambiguous message with an indeterminate hold time.

My favorite:
"We are experiencing heavy call volume. If you would like to leave your number, a representative will call you back".
I tried that. What do you know... nobody called back! So, I would call them again specifically to find out why they didnt. When asked why they didnt, the response is often silence. Or some lame excuse and once in a while, a disconnect!
The bigger the organization, the worse the customer service is!

"Urology Department. Can you hold?"