I am not licensed to practice in Michigan, so I will give you general advice.
I doubt that an attorney is going to be able to help you, at least not in the short term, and the cost would not be worth it.
I am assuming from your facts that the gas was shut off for non-payment. If that is the case then bringing the account current should rectify the probelm. Whether or not you were correctly billed is irrelevant. You were aware that you were using the gas for at least two months and should have been aware you had not paid for it.
If you feel you have paid the account current and can prove it, then forward that information to the gas company.