ugh I hate those with a passion, I once miscalculated the days it would take for some stuff to pend and I got massively hit and beaten with NSF chargers. I was -275$ and one of the charges was for a 99 cent itunes song. Thankfully I knew someone at the bank and got all but one reversed.
It's so stupid, I was pissed they charged me 33$ for a 99 cent itunes song. I mean, god forbid they had to pay 99 cents.