(1) All complaints for violation of these rules must be received in writing. No anonymous or oral complaints will be considered by the department.

(2) Upon receipt of a written and verified complaint from a person, an investigation will be conducted of the wholesaler's and retailer's entire records for the applicable period. If the department finds sufficient cause and believes prosecution of the alleged violation will aid in collection of cigarette and tobacco products taxes or assist in the regulating and enforcement of the tobacco Master Settlement Agreement, the department will proceed pursuant to 16-10-403 , MCA, and ARM 42.2.613 through 42.2.621.