You pretty much always have to threaten to cancel to get a good deal from them. I called back in February to try to negotiate a lower deal with one of the regular customer service reps and the dude wouldn't budge off the generic deals that are advertised on DirecTV's website. So I hang up and call back a couple of days later letting them know that I'm switching to the Playstation Vue service. They transfer me over to one of their cancellation/"account saves" reps who she instantly cuts my bill in half and gave me free HBO, Cinemax, Showtime, and Starz for for 6 months.
Moral of the story, always threaten to cancel. Don't waste your time with the other reps, they won't help you at all.