I had the same experience when I went there to buy DVDs for gifts. They didn't have what I wanted, but I couldn't get the saleswoman to leave me alone.
I finally told her: I have Verizon FIOS, and I'm staying with them. I'm not interested in anything else. She finally got the hint.
The next time it happens, I'm going to tell the manager that I didn't come into the store to be bugged by a DirecTV salesman.
I started in on my TV is the one eyed god rant with the Direct TV Guy.He looked at me as though I was a lunatic (my goal) and then retreated from me in haste.