Nicor Gas / unfair billing

I am still fighting a year old battle with Nicor Gas to no avail. The dispute centers around our pool heater and the increased usage during the summer months. I believe fraudulent billing practices force customers into their Budget Plan in which they make more money in finance charges. I have been paying my bills in full and on time and was surprised with a $550 bill for a second time because they under estimated my usage 4 months in a row despite an actual meter reading. If you have a pool heater and are experiencing the same runaround every fall, please post a response. Going to the the Citizens Utility Board with your support would help our cause.