G.R. No. 194461 - Zomer Development Co., Inc. vs. Special 20th Division of the Court of Appeals, Cebu City

Zomer Development Company, Inc. (Zomer), a domestic corporation, owned three parcels of land in Cebu City covered by TCT Nos. 59105, 59123, and 59214, mortgaged to International Exchange Bank (IEB) as loan security.
Upon Zomer’s default, IEB conducted an extrajudicial foreclosure sale (Notice posted October 18, 2001), emerged highest bidder, and received Certificates of Sale (November 19, 2001) entitling it to redemption rights.
IEB registered the Certificates of Sale on December 10, 2001, leading to issuance of TCT Nos. 361006, 361007, and 361008 in its name.

On February 18, 2002, Zomer filed in the RTC a “Complaint for Declaration of Nullity of Notice of Sale, Certificate of Sale & TCTs and Declaration as Unconstitutional Sec. 47, RA No. 8791,” challenging Section 47’s three-month redemption period for juridical persons as violative of equal protection.
The RTC furnished the Office of the Solicitor General (OSG) with a copy of the Complaint; the OSG did not participate.
On March 24, 2004, the RTC dismissed the Complaint for failing to implead the Republic (OSG), holding that ruling on constitutionality without the Republic deprived the OSG of due process.

Zomer appealed; on October 18, 2010, the CA Special 20th Division dismissed the appeal, classifying the case as a petition for declaratory relief and refusing to rule on Section 47’s constitutionality under its discretionary power (Rule 63, Sec. 5, Rules of Court).
Zomer filed a Petition for Mandamus before the Supreme Court to compel the CA to decide the constitutionality of Section 47 in CA G.R. CV No. 00288; Union Bank of the Philippines (UBP) appeared as private respondent (having acquired IEB).
The Supreme Court directed the OSG, Bangko Sentral ng Pilipinas (BSP), and Bankers Association of the Philippines (BAP) to comment on Section 47’s constitutionality.

Zomer (Petitioner) argued mandamus was proper as the CA unlawfully neglected its duty and violated Zomer’s due process by not resolving the constitutional issue.
UBP (Private Respondent) countered that an appeal or motion for reconsideration was the plain, speedy, and adequate remedy, that mandamus cannot substitute a lost appeal, and that the petition was moot since ownership was consolidated and Goldenway Merchandising Corp. v. Equitable PCI Bank had settled Section 47’s constitutionality.
The OSG, BSP, and BAP maintained that Section 47’s constitutionality was already definitively upheld in Goldenway Merchandising and in subsequent cases (White Marketing Development Corp. v. Grandwood Furniture; Spouses Limso v. PNB).

Whether a petition for mandamus is the proper remedy to compel the Court of Appeals to rule on the constitutionality of a statute.
Whether the case has become moot in light of Goldenway Merchandising Corporation v. Equitable PCI Bank.
Whether the Regional Trial Court erred in dismissing Zomer’s Complaint for failure to implead the Republic (OSG).