How can I find out if a technician is actually going to show up for my appointment

I  got an automated Xfinity text stating the technician was on his way, then one shortly thereafter stating the technician was onsite, and then an announcement that the technician had arrived and will be with me shortly.   No call or text from technician and no knock on door or doorbell.  I did see an Xfinity truck ride by, but it did not stop.  I continued to get automated texts that insisted the technician had arrived.  Finally, I got one that said “We’re sorry we missed you.  Your appointment is now cancelled.”  I had been standing on the front step in 20+ degree weather waiting for that technician from the first text notification.