I saved myself $30 just by making a 3 minute phone call!
You can try this with your car insurance and medical bills. I periodically call my insurance provider and have them look over my policy, maybe you are driving less miles or you got a new car that has safety features, those kind of things are sometimes eligible for a discount on your insurance premium. Always call if you have questions about a balance you owe on medical bills, could be a mistake or something they are willing to reduce, you can even receive a discount by paying a balance in full or up front before a procedure.
Try it on all your bills, remember: It never hurts to ask and it seems to work best when you call and ask nicely instead of demanding or threatening to quit, remember that old saying.......you get more flies with honey than with vinegar.