Why is it that AT&T Customer Representatives can schedule a technician dispatch but cannot cancel?

I called AT&T due to an internet/poor wifi issue. The customer rep performed a software reload and also scheduled a technician dispatch for the following day.

On the following day it appeared that my internet/wifi were back to working normally and so I decided to cancel the appointment. First, I tried to do so via ATT.com. I searched for the page which would allow me to cancel the dispatch , but instead was directed to a video which directed me to go to ATT.Com/appointmentstatus. When I went to that address after signing in (for the second time) a popup appeared that read: "Checking your services to help provide you with personalized support". Well this went on for what seemed an eternity until another message popped up indicating that the transaction timed out due to 5 minutes of inactivity. I then called AT&T customer service to rget the appointment cancelled.The representative did not seem to know how to cancel an appointment and asked for my patience. After 8 minutes, the call dropped. I called again and the next representative told me that she could not cancel the reservation and that I should wait for the technician to call and cancel at that time. When I indicated that this was unacceptable, that I couldn't understand how they could make an appointment but not break an appointment (felt like a Seinfeld episode) I was asked to hold again. At the 11 minute 20 second mark, the call was dropped again. Please note that the initial call to make the appointment and the next two calls to break the appointment were to the 800-331-0500 phone number. On the 3rd attempt, IO called the 800 288-2020 number, explained what had happened thus far and threatened to cancel all of my AT&T Services, included wireless. After 14 minutes on the phone, the representative confirmed that the appointment was cancelled. What the @#$% happened to AT&T customer service? The website and the app are terribly slow and have given me numerous issues (except for the bill pay of course) and the phone representatives don't seem to be empowered to complete the most simple of tasks. I am very disappointed in AT&T, a company that I worked for and was very proud of. The primary reason that I use AT&T is because their customer service was better than that of Comcast, even though the Comcast internet service worked better for me. Now there really is no reason for me to stay with AT&T.