Is it permissible, in Sharia, to use sealed and signed documents left by the merchant to present them as evidence to the judiciary and claim the outstanding debt?

It is permissible to use documents to prove a right established against a man, without exceeding the due amount. This is known as "Dhafr bil-Haqq" (obtaining one's right). Proving a debt with these documents is not considered a forbidden lie; rather, it is a permissible lie because it leads to a commendable objective, which is for the rightful owner to obtain his due.