Nicor Advanced Energy Nicor gas /Nicor Solutions I have been overcharged Naperville, Illinois

I feel so stupid admitting to this problem. I believe I have been bilked by Nicor. My husband enrolled in a lock plan a few years ago. I knew they had bad press and felt we over paid. When I received a letter that we have been adjusted down in billing do to our energy conservation I re-enrolled. We had paid $175 monthly but our new lock was $134. The first bill was $334. I called and they said that was for 2 mos. I put the bill on a credit card so I would always pay on time. The next two bills were for $412 in Nov. and Jan. ( I was being billed every other month and did not catch this). I did not have any statements to view since they were paid on my credit card. This month I received a bill for $266 for March. I had the statement. This bill was for Nicor Advanced Energy (lock12) $134 and Nicor Gas $131.

I am wondering if I have been double billed. I have not paid Nicor gas since I have been on the lock. I had always paid monthly by check to Nicor Advanced Energy and never more that $175. It is a lock and it went down in cost, yet my costs have soared. I have been reading the posts and fear I am doomed. I know I have not stayed on top of this. They sound like they make a habit of cheating. What options do I have?