G.R. No. 192602 - Spouses Villaluz vs. Land Bank of the Philippines

Paula Agbisit, chairperson of Milflores Cooperative and mother of petitioner May S. Villaluz, sought P600,000–P650,000 for her flower business expansion in 1996.
May and her husband Johnny Villaluz allowed Agbisit to use their land in Calinan, Davao City (TCT No. T-202276) as collateral.

On March 25, 1996, the Spouses Villaluz executed a Special Power of Attorney (SPA) in favor of Agbisit authorizing her to negotiate and sign documents for the sale, mortgage, or disposition of the property, without any prohibition on appointing a substitute or specifying amounts.
On June 19, 1996, Agbisit appointed Milflores Cooperative as her attorney-in-fact to obtain a loan and execute a real estate mortgage. On June 21, 1996, the cooperative mortgaged the land to Land Bank for a P3,000,000 loan; on June 24, 1996, it also executed a Deed of Assignment of Produce/Inventory as additional collateral. Land Bank released P995,500 on June 25, 1996 and the balance of P2,000,500 on October 4, 1996.

Milflores Cooperative defaulted on its loan obligations. Land Bank filed for extrajudicial foreclosure; auction was set for October 2, 2003, and Land Bank was the sole bidder.
The Spouses Villaluz filed a complaint in the RTC to annul the foreclosure. The RTC held that, under Civil Code Article 1892, Agbisit validly appointed a substitute and dismissed the case. The CA affirmed in a September 22, 2009 Decision and denied reconsideration, prompting this petition for review.

Whether Agbisit, as agent under the SPA, validly appointed Milflores Cooperative as substitute under Civil Code Article 1892.
Whether the real estate mortgage executed on June 21, 1996 is void for lack of consideration because the loan proceeds were released only on June 25, 1996.
Whether the Deed of Assignment of Produce/Inventory extinguished the SPA or the underlying loan obligation.