The only time someone leaves a review for their utility on yelp is when they're really pissed. It's not a restaurant, you don't have a lot of choice, so why bother with reviews?
Chances are it will be fine. Occasional human error on their side might be an issue. Occasional issues with, say, people having a gas leak and not knowing will also hike prices way up.
Relax, there's no way a legitimate utility is charging $600 a month for normal amounts of gas use.