Getting paid by Direct TV for work they asked me to do for them

I did work for att/direct tv's office in Peoria az. I was told by the person who hired me to send a bill to the place when the landlord received their rent check from. I did so, and received a form letter telling me that it was the wrong place.
I want to talk with Direct TV's Accounts Payable Office to find out where I send my bill. I have been unable to get any telephone numbers which are in service for ATT/Direct TV's corporarte or business offices. Can anone help me?