CCP §729.070: (a) If the purchaser and the person seeking to redeem the property disagree on the redemption price or as to whether the person is entitled to redeem the property, or if the purchaser refuses the tend

(a) If the purchaser and the person seeking to redeem the property disagree on the redemption price or as to whether the person is entitled to redeem the property, or if the purchaser refuses the tender of the redemption price pursuant to Section 729.080, the person seeking to redeem may file a petition with the court for an order determining the redemption price or whether the person is entitled to redeem the property. The petition shall be filed before the expiration of the redemption period. At the time the petition is filed, the petitioner shall deposit the undisputed amount of the redemption price with the levying officer, if deposit has not previously been made, and give written notice to the levying officer or trustee of the filing of the petition. (b) The petition shall be in writing and shall include the following statements: (1) The amounts demanded to which the person seeking to redeem objects and the reasons for the objection. (2) Any amounts offset to which the purchaser objects and the justification for the offset. (3) The status of the petitioner that qualifies the petitioner to redeem the property. A copy of the papers required by subdivision (a) of Section 729.060 shall be filed with the petition. (c) The hearing on the petition shall be held not later than 20 days after the date the petition was filed unless continued by the court for good cause. (d) Not less than 10 days before the hearing, the person seeking to redeem the property shall personally serve on the purchaser a copy of the petition together with a notice of the time and place of the hearing. (e) At the hearing on the petition, the person seeking to redeem the property has the burden of proof. (f) At the conclusion of the hearing, the court shall determine by order the amount required to redeem the property. The determination shall be made upon affidavit or evidence satisfactory to the court. (g) If an amount in addition to that deposited with the levying officer is required to redeem the property, the person seeking to redeem shall, within 10 days after the issuance of the order, pay the additional amount to the levying officer.