Does PCHC have jurisdiction over a case even if the checks subject of litigation are admittedly non-negotiable?

Yes. Viewing these provisions the conclusion is clear that the PCHC Rules and Regulations should not be interpreted to be applicable only to checks which are negotiable instruments but also to non-negotiable instruments and that the PCHC has jurisdiction over this case even as the checks subject of this litigation are admittedly non-negotiable.Moreover, petitioner is estopped from raising the defense of non-negotiability of the checks in question. It stamped its guarantee on the back of the checks and subsequently presented these checks for clearing and it was on the basis of these endorsements by the petitioner that the proceeds were credited in its clearing account. The petitioner by its own acts and representation can not now deny liability because it assumed the liabilities of an endorser by stamping its guarantee at the back of the checks. (Banco de Oro vs. Equitable Banking Corporation G.R. No. 74917 January 20, 1988)