Card Holder Services incessant calls

This is getting worse and worse.    The calls come in virtually every day, now on our cell phones as well as land line.    I have stuck with it a couple of times to speak to an operator and complain.    As soon as I have said, "How can I stop these calls," the operator has instantly hung up every time.    They clearly have instructions not to waste an instant on naive people who may hope to stop these calls.   I should add that my wife and I are on the Do Not Call government registry; but obviously it does not matter in this case.