I ran into their scam billing/ cancellation problems last year. They claimed I owed a balance when in fact they owed me money for stopping prepaid service early. Well long and short (most people know of the rediculous amounts of time spent on the phone and writing letters to them and their scam collections people) is that you really need to go sue them in small claims court. I did this and won since they never show up for court and you win a default judgment in most cases. I sued for $500 even though they owed me about $20, but after I calculated my time invested...well you guys know even that's not enough. I did it this way:
Go to your local county courthouse, fill out the small claims paperwork. You will need to contact the LA county sheriffs dept. to serve them a summons to court, they will walk you through the process give you the address and payment information to have directv served papers at their headquarters at 2230E. Imperial Hwy El Segundo, CA 90245. I do not have the phone number, but it is the LA county sheriffs Dept. Inglewood branch 1 regent st. Inglewood, CA 90301. They will serve the papers directly to Directv and you will have to appear in your local court against them (if they show up...unlikely). Directv mailed me a check about 60 days after the court notified them of the judgment against them.
Here's what's funny. I got another letter from DTV the other day saying I still owed them the original amount regarless of them losing in court and issuing a check. The stupidity of management here is beyond belief. I am sending one last letter and then I am sueing again if need be. Good luck, hope that helps.