G.E.M. Federal Credit Union G.E.M.FCU Abusive fees Minot, North Dakota

I recently had a loan due 31Nov in the amount of $558.97, which I paid off on their website in full.  Immediately after applying the payment, my loan still showed I owed another $5.68.  I immediately tried to pay this, but recieved an error. 

My bank usually would call me to fix the error, or simply correct it.  Instead, they left the charge in the file for a month before calling me.  I did not call them because I work nights and their hours are the opposite of mine.

A month later, the loan officer calls and advises me I now owe a $15 penalty because their website didn't work properly.  I told her my story, and she simply said there isn't anything they can do to fix their web system, and it wasn't their fault!

I will not pay the $15 late fee as I was not late.  I can afford it, it is not a lot of money, it is the principle of the idea.  Banks are getting too powerful and they need a reality check.  Where would they be without my money?  This is not the first time they have done something like this either....I just don't know who to go to, and since the dollar amount is so small I feel like this is petty, but if they do this to everyone they are making a mint.