I agree, you should not have been charged. If they didn't do what you asked, you should not have had to pay.

The guy at my Staples ran it once and got it exactly the right size (using a preprinted sizing chart) but the ink was a little light. I asked him to run it again a little darker which he did and didn't charge me for the second copy. He gave me both, laminated the good one and charged me only $6.00 total. By the way, he did all this while I waited.

I don't know if it will help but you can use my experience to complain to your Staples. They obviously have an inexperienced person working there.