Cancelled Installation Appointments

I signed up for gig internet but I can't seem to get it installed.  Twice the technician has cancelled the appointment while I was home waiting for them to arrive.  Each time, the Xfinity Assistant text string tells me that the technician is coming and even that he's outside getting ready and then that the appointment was cancelled.  Why is this happening?  I'd rather not wait around for someone who isn't going to show up.  I've rebooked through Live Chat both times and the person I was chatting with seemed to have no idea either.  What's the point of chatting with someone that has no idea what is going on?  Connect me with the technician or his boss.  At least it wasn't some dopey AI.  Should I go to the local retail store?  Would they have a clue?  Why is Comcast always unreliable?  How do I get my internet installed?  Just keep trying?  How many appointments will it take?  5?  10?  50?