Your guess is wrong. When you sign up for something, your agreement with the provider will be governed by the contract you make with them. MasterCard are not a

Your guess is wrong. When you sign up for something, your agreement with the provider will be governed by the contract you make with them. MasterCard are not a legislative or judicial body, and we should be very wary of allowing organisations like that with monopoly/oligopoly control of such a fundamental aspect of the market to exercise quasi-judicial powers.