Free in While in Credit = Fair While in Credit
There is no such thing as free banking. While you are in credit, the bank makes good use of your money and maybe pays you a few bonbons to keep you quiet.
Once you are not in credit then the gloves are off. You then become fair game for any unfair trick, any unfair charge, any unfair tactic which is calculated to keep you in debt so that you remain a nice productive Cash-Cow until your udders are dry and you are then sold on to the nearest DCA.
This is why 'Free While in Credit' really means
Fair While in Credit