Upon application , if the director determines that any tax, interest, or penalty has been paid more than once, or has been erroneously or illegally collected or computed, the tax, interest, or penalty shall be credited by the director on any taxes then due from the taxpayer under this chapter. The director shall refund the balance to the taxpayer or the taxpayer's successors, administrators, executors, or assigns in accordance with section 231-23. No credit or refund shall be allowed for any tax imposed by this chapter, unless a claim for the credit or refund is filed as follows:
Paragraphs (1) and (2) are mutually exclusive. The preceding limitation shall not apply to a credit or refund pursuant to an appeal, provided for in section 237D-11.
As to all tax payments for which a refund or credit is not authorized by this section (including, without prejudice to the generality of the foregoing, cases of unconstitutionality), the remedies provided by appeal or by section 40-35 are exclusive.
HRS § 237D-10