Need to set up access points

First off, I am NOT an IT geek. My husband and I run a home based business with four locations on our property needing reliable internet service.  The Comcast installer was here earlier this week and she installed the new modem and gave us two access point units. 

She didn't tell me how to set them up! I managed to get one to working, but not the other.

I found my way to the area in the app showing me how to set the access points and actual place to do it, but was the equivalent of "grayed out." I couldn't enter the necessary information.

i want the signal to go to the other two locations.

The app said internet service was not set up.  And now I can't find my way back.

Calls to tech support were utterly useless. I wanted to talk to a live human to walk me through this mess.

Is there a way to contact a live human?  I know I'm kvetching but at least a live human is reading this.

Thank you,

Lydia