How do I contact AT&T to cancel?

I recently changed from Time Warner to AT&T Uverse but have never been more dissatisfied and never had a company try to cover up their incompetence by trying to steal from me.
I need to speak to someone in the United States about immediately fixing AT&T mistakes, canceling all services and being refunded my expenses or who to contact in the legal department about [Edited to comply with Guidelines]
AT&T is by far the worst company for service I have ever engaged. Embarrassing since they are a service industry. Adding insult to injury, I am a retired soldier and 100% disabled because of 25 years of service. I'm so proud that I made numerous sacrifices, stateside and in multiple combat zones, so that I can be disrespected and taken advantage of so egregiously when I return to the country that I fought to defend. God Bless America but shame on AT&T.