I had a similar problem several years ago. I went and looked at my meter and it was spinning way too fast so I went to my panel box and flipped off the breakers one by one checking the meter in between, finally flipped a breaker and like a car slamming on its breaks the meter stopped spinning. Then I went and unplugged everything on that circuit turned it back on and plugged things in one by one. Turns out I had a slight ground on my stove which wasn't enough to trip the breaker (didn't have a GFCI) but enough to burn up my bill.