How to piss off postal workers

I had a job application that I had to send overnight, so I put it in a manilla envelope, sealed it, and headed to the post office. I had just gotten off work, and only had 15 minutes to walk/run across campus to get to by car, and then drive like a bat-outa-hell to get there a few minutes before they closed. I was the second to last person in line before they locked the doors. I finally got to the front of the line, asked for delivery guaranteed by Friday, and he told me I needed to use express mail, which had it's own envelope. Now for some reason they made the express mail envelope an inch smaller than a manilla envelope in all dimensions. I started to try and fold the corners of the envelope without folding the materials inside, and in the mean time gave him my credit card to pay for the postage. I decided that I should just rip open the manilla envelope and put the materials directly into the express mail envelope. So I first opened the metal clasps holding the middle of the manilla envelope and then ripped open the seal... and blood started pooring out of my finger and onto the envelopes. I had cut it on the metal clasp! So now I got several people in the back running around looking for a paper towel and a bandaid, and now there was blood on the envelope that he had just put postage on. This meant he had to issue a refund and then buy the postage again... which he didnt know how to do, so he needed help. In the mean time someone else had carefully picked up the bloody envelope and put it in a hazardous material bag. But of course they needed the old postage to issue the refund, so they needed to get it out again and get the postage off it. Finally, about 20 minutes after they closed, they finished my "simple" transaction which should have taken only about 2 minutes. Sorry, no pictures to post of this event!