Contacted agent through Zillow and Realtor....

[Brandon Hoffman]

It isn't illegal to not return a message. They did you a favor as you can rule that agent out now and find someone more responsive.

[yrrek]

So how does buying a house work if Zillow does not reply
If I am in search of a house and I drive past one with a for sale sign why can’t I just call the realtor on the sign?
Why do they advertise if you can’t call them
I’m feeling a little confused on the process

[Diana Holbrook]

You can call the realtor on the sign, just realize that they represent that seller, not you. What you really want to do for the long term is find an agent you like to be your buyer's agent and help you find places, and get in the ones you want to see, advise you about the process, and help you ultimately close on one.

It might be a realtor you meet from a sign, or better yet... ask your friends or locals in a facebook group for recommendations for good, responsive buyer's agents.