Another Bank Scam

I work for the Federal Government, and get paid every two weeks.  I use direct deposit, and usually, it comes on a Thursday, but lately it's been tending toward Friday.  Apparently, the payment got to my bank -- credit union, actually -- Navy Federal Credit Union to be exact -- on Friday after 630 pm EDT.  I looked for the money on Saturday and Sunday but it never showed up.  I looked again Monday morning and there was an indication that the direct deposit had occurred, but my balance was still at zero, and the indication said the amount would be credited the next day.  So Navy Federal had several thousand of my dollars from Friday to Monday, during which time they were charging me 15% on the money that I had recently overdrawn (that's the deal for overdraft protection -- no fees, but high interest), counting on the paycheck to come in.  I called Navy Federal and they explained that essentially the above had occurred.  The deposit had come in on Friday, and if it had come in before 630 pm, it would have been mine to use starting then (I think that's what they said).  She then checked the "notice" which came with the money, which -- for reasons that make absolutely no sense -- supposedly said that Navy Federal shouldn't give me my money until Tuesday.

She claimed that the "notice" was from my employer, i.e. the Federal Government.  In other words, the Government "gave" the money to NFCU on Friday, but wants NFCU, not me, to have it until Tuesday.  I must be missing something.  Before I join another bank I will definitely check what their policy is on releasing funds, esp. direct deposit funds.  How hard would it have been for the bank to give me my money on the weekend?  If there's a law that permits them to do this, wouldn't repealing that law give a nice boost to the economy?  A bunch of citizens would get their paychecks before, not after, the weekend.  And banks wouldn't essentially be stealing interest from their customers.