Can i be held liable for a hand written electric bill?

ok so here is the deal i was living some were in my camper over the winter and electric was paid by the kilowatt to the owner of the park... well here is were the problem is. i heated my camper all winter on a 12 volt propane heater and the camper and most everything else is 12 volts aside from a few things like a tv they said over the corse of 4 months i used 7038 kilowatts which amounts to about $800. which i don't believe is correct or even possible on a 15 amp service. i asked to see an electric bill from the electric company. and they said they didn't have an electric bill for just my lot that they got those readings off of the electric meter that they have installed on my lot. i think they miss wrote something down and have refused to pay. they said that they were going to take me to court for the money will that hold up for them in court.