first premier bank charging me late fees when i am not late sioux falls South Dakota

FP is a "Sub-Prime" card, and a credit card that is a "last resort" where no other creditor will touch you.  I find it interesting how in two sentences you claim that they are the only company that "hides" their number, yet you also calim that they are the only company you are having issues with.  So here is a question...if you aren't having issues with other cards how do you know they don't hide their number?  Seems like there be more to your claims...but with that said.

What does your Credit Card Statement show?  Does it show at least your minimum payment being made by the Due Date?

You say that you pay "early" and this may be your problem.  Credit Cards are considered an "open ended" account, meaning that by Federal law any charge and/or payment in a certain billing period must be applied in that period.

So if you happen to have a payment due date of the 21st, and your biling period runs from the 1st of each month(for example).  If you make a payment on June 1st, it could get applied to your June bill.  But if you made it on May 31st, it would still get applied to your May bill and you still have a minimum payment due for June.  If you fail to make the payment in June you are late even though you "think" you paid early for June.

So as I said once you review your statements, this is a very high chance of what you will see.  In this case then you need to fix by making another payment, which actually is a plus for you because it reduces the Interest you are paying them because you are getting your balance down.