Dishonest door-to-door ATT sales people

ATT
Anybody have a good phone number and contact name for reporting door-to-door sales people preying on the elderly? I've tried calling general support number (5942), sales (2020) "escalation" (0789). Have tried to speak to a manager each time. I just get put on hold forever or told that the manager is busy.

In meantime, please advise your loved ones of the following scam:
ATT salesman wearing badge knocks on door to let homeowner know that neighborhoods' old wiring and in particular wiring on homeowner's street is being replaced. Homeowner will now have faster connection. This is just a friendly visit not selling anything. Just an FYI about what ATT is doing for its customers. But--will need to replace old modem for her free of charge. Just need to sign this piece of paper ...

He didn't identify himself as a salesman said he was an installer (implied he was PR person).

Thank goodness I was called before anything was signed. I actually talked to this person on the phone and before the conversation ended, I was given 3 different stories. the last of which he finally admitted that he was upgrading her ATT phone and internet and switching her cable to ATT. REALLY?!

I have the paperwork, my relative would have signed which included a contract, a new modem, switching cable service from Comcast to ATT and more.

My relative had no idea what was being signed. The salesman was, "so polite and said I didn't have to pay for anything".

Is there anyone at ATT willing to step up to the plate to fire people like this? My relative let this person into her home without thinking twice because she trusts ATT. Would your elderly relative do the same? This must be stopped!