Any taxpayer may contest any proposed assessment or license fee made or determined by the commissioner by filing with the commissioner a written protest at any time within 30 days from the date of notice of the proposed assessment or license fee or within such other time limit as may be specified within the notice of proposed assessment or license fee, if a different time limit is specified. All protests shall be prepared in the form and contain such information as the commissioner shall reasonably require and shall include a summary statement of the grounds upon which the taxpayer relies and his reasons for disputing the finding of the commissioner. The filing of a written protest, a petition for redetermination of a deficiency, or a written request by the taxpayer for additional time for filing such a petition shall toll the period of limitations for making an assessment until the petition is denied by the commissioner or the request is withdrawn in writing by the taxpayer. In the event the taxpayer desires a conference or hearing, the fact of such desire must be set out in the protest. The commissioner shall grant a conference before his officers or agents as he may designate at a time he shall specify and shall make such reasonable rules governing the conduct of conferences as he may deem proper. The discretion given in this Code section to the commissioner shall be reasonably exercised on all occasions.