Is the plaintiff entitled to demand 15,0 riyals from the debtor, or to annul the contract, take possession of the shop, and deduct the debt from it?

The solvent debtor must repay his debt when it becomes due. He is considered unjust if he fails to do so, for the Prophet, peace and blessings be upon him, said: "The delay of a rich person (in paying his debt) is injustice." If he is insolvent, then he must be given respite. The creditor is not entitled to demand the amount of property transfer or contract cancellation unless there is an agreement. The creditor has the right to refer the matter to the Sharia court to compel him to pay.