For $60, just dispute the charge. Make the dispute much, much, much shorter and to the point than your OP.
A good chance that Hertz never bothers to reply and your temporary credit simply becomes permanent.
You do need to be a bit concerned that Hertz either places you on a DNR list if it shows what amounts to a debit balance or you are simply informed that you owe $60 before you are permitted to drive off with your next vehicle.