Section 27A. An executor, administrator, trustee, grantee, donee, survivor or beneficiary aggrieved by the assessment of a tax under this chapter may apply in writing to the commissioner, upon a form approved by him, for an abatement thereof at any time within one year after the date of the certification of such tax or within one year after the date of payment thereof, whichever is later. The commissioner shall, if requested thereon, grant the applicant a hearing upon his application. If the commissioner finds that the tax is excessive in amount or illegal, he shall abate the tax, in whole or in part, accordingly. If the tax has been paid, the state treasurer, upon certification of the commissioner, shall repay to the applicant the amount of such abatement without any appropriation therefor by the general court. The decision of the commissioner shall be final. The commissioner shall give notice to the applicant of his decision upon the application. This section shall be in addition to and not in modification of any other remedies provided by this chapter.