1/12/23 UPDATE:

Just got the new bill since the one discussed here. It's for a 3 week period and the bill came to $133 for just 52 therms used with an actual read-not estimated. FINALLY the reading was accurate and matched up to the daily readings I had been doing on the meter. We literally have not turned on the heat since the last bill. In fact for this cycle, we used about 50% less gas than the Dec 2021 bill.

With that said, I'm not sure if I still have any "leg to stand on" in trying to dispute the insanely high last bill. How can I tell them something was/is wrong even though the most recent bill was accurate? Thoughts?