Get on the phone and start screaming. Don't take no for an answer. Tell them their service sucks and then tell them all that went wrong (also make stuff up.) Ask for a manager if necessary. Keep asking to speak to different people until you get an answer you are satisfied with. Once you've done that, ask for the person's name and get their extension number. Then go to your local store, tell them who you've spoken with, what they said they would do for you, and then get it done.
I've never done this, but I've seen my mom do it a handful of times with Verizon. Works like a charm.
Then again, everyone in my family still uses Verizon.
