Last January 2012, a former kabarangay offered my mother to sell their lot property at a total cost of P50,000 on installment basis. The seller is living in a diffirent province and she has her niece to received the payment for her. MY mother completed the payment in June and both agreed to see in person to finalize the contract of sale. However, they need the signature of the seller's spouse in order to close the sale. Hence, my mother paid the amount in full while the seller went home with the contract for her spouse to sign saying that she will send the document through LBC. However weeks passed and my mother didn't hear from the seller until recently through her niece informning my mother that the spouse don't want to sign the sale for a reason that the price was not enough for the property and they are asking an additional of P15,000. They said, they spent so much when they bought the property and they feel they sold it cheaply for P50,000.00.
We feel that the seller deceived my mother and playing her for a fool. It has been six months since my mother started paying the installment and only now they are saying that an additiional payment is necessary. They should have informed and asked my mother for their asking real asking price affront before any payment was made and not after the full payment.
My question is, is the agreement binding already on the previous amount of P50,000.00? Can my mother demand delivery of the transfer of title for the property? Please advice.