ATT equipment router return

Hello! I moved my internet to a new address and brought the original router I had at the previous address. I got an automated call yesterday that I need to return missing equipment followed by a phone number. I couldn't catch the phone number.

Nonetheless, I already paid for the router I'm using right now and wasn't sent a new one nor charged for a new one. I'm wondering if I can still keep the current one? Do I need to return it or is there a way that I don't need to make that happen. Is there someone I can talk to directly about this. On the phone call when moving the address I clarified with support that there isn't anything else that I needed to do. 

Thanks