The council, after notice and hearing, shall revoke a permit if it finds the retailer has substantially violated the provisions of this chapter or Iowa Code, Chapter 453A, or if grounds exist that would be sufficient for refusal to issue such a permit. The clerk shall give five days’ written notice to the retailer by mailing a copy of the notice by certified mail to the place of business as it appears on his application for a permit. The notice shall state the reason for the contemplated revocation and the time and place at which he may appear and be heard. The hearing shall be held at the regular meeting place of the council.