"Have you thought about getting a job working for better people" is incredibly patronizing, akin to asking a fast food worker why they're not working at a real restaurant or someone at a huge, bulky conglomerate why they're not working for Google. The rep knows that their script isn't designed to help you, just like someone working at McDonald's knows that their burgers aren't the best in town, but they also have to pay rent at the end of the month so they're going to stick to it.

Being nice to customer service reps is the best thing you can do and is the easiest way to get them to go out of their way to help you. Chances are the caller before you was kind of a jerk, and the caller after you will probably be kind of a jerk, so if you approach the call in a nice manner and are polite and patient you'll stick out in a good way and the agent will be more inspired to assist you. It's possible or probable that they'll still be hamstrung by corporate regulations but like they say, you'll catch more flies with honey than vinegar (or however the saying goes).