I don't know if any one said this and I'm not trying to be a jerk but since you are getting 30 calls a day, it seems to me that you could raise your prices. Pick up new accounts that pay more and slowly weed out the ones that are low.
“Life takes on meaning when you become motivated, set goals and charge after them in an unstoppable manner.”
"There is no such thing as failure. There are only results." – Tony Robbins