Mastercom

Every stage of a dispute, from the retrieval request through chargeback and representment to pre-arbitration and arbitration, is logged as a case in Mastercom, with deadlines the system counts down by itself. Miss one and you lose, however good your evidence was. Banks either work in the web interface or wire their own case-management tools to the Mastercom API.

Visa's equivalent is Visa Resolve Online. Merchants rarely touch either directly; they see their cases through the acquirer's portal, usually a few days late, which makes the deadlines considerably tighter in practice than on paper.