Every holder of a license or a renewal thereof, as provided for in this section, desiring to continue the transaction of business as provided for in this chapter, shall at least 30 days prior to the expiration of such license or renewal thereof make application to the Commissioner on forms to be provided by the Commissioner for a license renewal. The Commissioner may mandate that applications for renewal shall be treated as new applications if said renewal applications are not on file with the office of the State Bank Commissioner at least 30 days prior to the expiration of such license or renewal thereof. Licensees who have not complied with supervisory letters or who have not paid any supervisory assessment or examination fees when due may be refused license renewal.