If any unused blank way bill form no., referred to in rule 100, rule 103, or rule 104, or rule 108, obtained by any person, casual dealer, or dealer who is not registered under the Act or obtained by a registered dealer, under any of these rules is lost, destroyed or stolen from his custody, such person, casual dealer, or dealer who is not registered under the Act or registered dealer shall, within seven days from the date of such loss, destruction or theft, report the fact of such loss, destruction or theft of such way bill form no.s to the appropriate assessing authority or the authority referred to in sub-rule (3) of rule 110A or the appropriate authority from whom such way bill form no. was obtained.