...on frustration

I did something really annoying a few weeks ago.  I washed our mail key and it disappeared into the abyss that is our washing machine.  As a result, I had to go down to our horrible post office and request a new mail key.  Easy enough, right?  They told me it would take a week to get the new key so I didn't bother putting our mail on hold.  Well here I am, two and a half weeks later and still no key.  I have called four times and was told that someone would return my call.  Want to know how many calls I have gotten back?  ZERO.  Oh, and I went down there on Friday and the lady took my name and number and told me she would call me back well guess what, she hasn't.  I called again this morning and the "lady who is in charge of they keys is off today".  Well, of course she is!  The best answer anyone has given me is that they will call me when it comes in.  I finally put my mail on hold because, let's face it, I need to get my mail!  The other thing I did this morning, that I have never, never done before, is file a complaint against the post office.  I feel kind of like a brat doing this because I'm really not one to make a stink about anything but honestly, I am so annoyed.  Thoughts?  Am I being unreasonable?