Trying to activate new 4K boxes

I went to the Xfinity store and got the latest 4K boxes to update my home TVs.  I couldn't do the upgrade right away so the rep gave me a number to call: 855-652-3446.  The phone menu is abolutely maddening.  No way to talk to someone only one response available to text you a link to activate a gateway.  I want to activate cable tv boxes but it keeps sending me to the gateway link.  No way to talk to someone or get tech support, then it just wants to step you through the trouble shooting process. This approach to customer support just shows how much Comcast cares about customer service. We've been customers for over 20 years and this insulting. Who do I have to call to activate these new boxes?