violate a duty(toward – перед; similar to an obligation: "do not and will not, directly or indirectly, violate, infringe or breach any duty toward or rights of any third party"ART Vancouver)
default on a payment(заемщика перед кредитором: In 2007, Gold Star Air defaulted on their payments to Boeing Commercial Aircraft, who sent representatives to Abijan to repossess the aircraft.ART Vancouver)