Why did Xfinity cancel my confirmed appointment formed

I have been having intermittent outages. Someone came out a few weeks ago. Could not find issue and when they arrived internet was working. Now it is happening again. I have done everything that I was directed to do by the chat bot. Tightened, reset, etc. Still happening. Had a confirmed appointment for 9/5 and received a text today that it was cancelled, no reason given. Why was it Cancelled?