I have seen this type of metering in many marinas, so I would have to say it is a legitimate way to bill you. As for "rigging" the meter, I suppose it's possible, but those meteres are almost certainly preset at the factory and may not even have an adjustment. You could probably check it by removing all load from your line, then plugging in a single appliance of known wattage, like a 1000 watt hair dryer. Run it for an hour and see if the meter has registered exactly one KWH.
Dave
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