Why is AT&T so incompetent that they would not even call the number they failed to set up as the simplest QA step

It's been 3 months and they've still failed to set up my landline phone. I've called tech support maybe 6 times and finally they said, "don't worry, we'll call you when we fix it and we won't bill you"

All of that was (Edited per community guidelines). I just got several bills in the mail including a threat to cancel my service + charge me a reconnect fee. (Edited per community guidelines).