You said there is no competition and there is no alternative. Well, somebody called Bill Gates was quoted only six months ago as saying he could go into the debit card business because he could do it more cheaply than anybody else.
If they set their fees too high, any of the companies, this is going to provide an enormous incentive to some entrant to enter the business and knock them dead with a lower, cheaper, better-value product. This happens all the time. Schumpeter called it creative destruction. If you put in price controls, you end creative destruction. You end innovation. Then we'll look like Cuba or some country like that.