The tax levied by this Article does not apply to the storage or use in this Town of tangible personal property acquired in this Town, the gross income from the sale, rental, lease, or license of which were included in the measure of the tax imposed by Article IV of this Chapter; provided, however, that any person who has acquired tangible personal property from a vendor in this Town without paying the Town Privilege Tax because of a representation to the vendor that the property was not subject to such tax, when such claim is not sustainable, may not claim the exclusion from such Use Tax provided by this Section.