So you are telling the bank you lent someone money, did not get paid back, so now I want to dispute? Their answer will be, our terms do not allow others to use your cards, and you are liable for any charges on your account. Banks are not a gemach
Does it say anywhere in the T&C that if you use the card on any way other than they want you to, that you forfeit your right to dispute the charges?
Also, there is a LAW about being dissatisfied with the goods or services if the charge is over $50 and depending on location of your home/merchant. You must try in good faith to reconcile, but when all else fails, you are not required to pay. Why can this not protect you even of you made charges against t &c?