The Nassau Office of Consumer Affairs says a town of Hempstead senior citizen complex was ripped off by an oil truck company.SJ Fuel Co. Inc., out of Brooklyn, allegedly billed the Park Gardens complex for heating oil that investigators say never went into the tank. Consumer Affairs says the scam was uncovered when a Garden City police officer stopped the fuel truck for a routine safety check. The officer found a delivery ticket that showed 500 gallons of heating oil had been delivered to the senior facility, when in fact, the driver's next stop was that facility.The case is now in the hands of the Nassau District Attorney's office.