@burcinc-- Yes, a new fee is charged every time a person makes a purchase while in overdraft. Not only that, but some banks charge more fees if an account remains in overdraft more than a certain period of time. For example, a bank may charge a fee for every two weeks that an account remains in overdraft. This may happen even if the individual is not withdrawing any more money.
So these charges and fees can accumulate rather quickly and make it even more difficult to get out of.