(1) When an order and notice of assessment has been served upon or mailed to a delinquent employer, the employer may within thirty days file an appeal with the department, stating that the assessment is unjust or incorrect and requesting a hearing. The appeal must set forth the reasons why the assessment is objected to and the amount of premiums, if any, which the employer admits to be due. If no appeal is filed, the assessment shall be conclusively deemed to be just and correct except that in such case, and in cases where payment of premiums, interest, or penalties has been made pursuant to a jeopardy assessment, the commissioner may properly entertain a subsequent application for refund. The filing of an appeal on a disputed assessment with the administrative law judge stays the distraint and sale proceeding provided for in this title until a final decision has been made, but the filing of an appeal shall not affect the right of the commissioner to perfect a lien, as provided by this title, upon the property of the employer. The filing of a petition on a disputed assessment stays the accrual of interest and penalties on the disputed premiums until a final decision is made.

(2) Within thirty days after notice of denial of refund or adjustment has been mailed or delivered, whichever is the earlier, to an employer, the employer may file an appeal with the department for a hearing unless assessments have been appealed from and have become final. The employer shall set forth the reasons why such hearing should be granted and the amount which the employer believes should be adjusted or refunded. If no appeal is filed within said thirty days, the determination of the commissioner as stated in the notice shall be final.