Ariz. Rev. Stat. § 43-563
The department of revenue may recover any refund or credit or any portion which is erroneously made or allowed, together with interest at the rate determined pursuant to section 42-1123 from the date the refund was made or the credit allowed, in an action brought within two years after the refund or credit was made in a court of competent jurisdiction in Maricopa county in the name of the department of revenue. The action shall be tried in Maricopa county unless the court with the consent of the department of law orders a change of place of trial. The department of law shall prosecute the action, and the rules of civil procedure in the superior court of Arizona, as amended, relating to service of summons, pleadings, proofs, trials and appeals are applicable to the proceeding.
A.R.S. § 43-563