Want to upgrade equipment.

Looking for a customer service phone number to contact to see if I can upgrade our wireless gateway router that is no longer supported.  We have had this gateway for over 5 years. All I get is the go-around with the live "Chat" service Comcast has.  Can I just make an appointment and take it into a local store and ask them for an upgrade?  I'm not willing to drive to the local store miles and miles away to find out that I can't upgrade it.