Hopefully the listing agent isn't the broker of the company he represents. I can help you find this out or maybe you can on your own.
Find out who the broker is of the real estate company. If you have your own agent, have them write up an offer on the house & DIRECTLY PRESENT THE OFFER TO THE BROKER.
I suggest you get an agent to represent you. However if you're doing this on your own, go over to the Real Estate office & SPEAK TO A BROKER OR MANAGER DIRECTLY.
Tell them you're PO'd and you want to make sure your offer is being reviewed!!
If neither of these things work. Go to the local board of Realtors for the Northridge area & file & ethics complaint.