They are strange.
I got hired else where, but prior to that pro-transport called me and left a message asking for an asap call back to set up an interview. I returned the call within 15 min, but got no answer and left a message. Two days later, after not getting a call back, I called again. But this time the voicemail is full - So I sent an e-mail.
It's been over two weeks since then and I never did get a return call or return e-mail.
Good luck, man. I know you've been looking for awhile. The company that hired me said they get 20 EMT applications a day. A DAY! It's crazy considering how crap the pay is.