PECO AND MY 339.66 ENERGY BILL

I received my energy bill for the month of December. Normally this year, my bill has been roughly 40-60 dollars. This month it is 339.66. I am never home, my husband is never home. We have no kids. We are religious about turning appliances, the computer, lights etc off. We keep the heat at 65 degrees. How in the world could we have used so much energy? Especially considering we were not home for 2 weeks straight for the holidays. And it has not been all that cold for that long. I emailed the customer service and tried calling but have reached no one. I refuse to pay this bill until I speak to someone and get this resolved. It looks like a lot of other people have filed similar complaints here. Has it helped?

Thanks,

Stefania