I also have had similar experiences. One in particular at one of the big box stores (a national chain). The end of the bolt was 2" longer than the cut that I wanted. I said I would take the additional 2" at no charge to keep them from having that small and scrap. The employee said "Oh, my boss says I cant do that". So, as a result I had her make the cut and left them with a 2" scrap that probably wound up in the trash can. I sure felt better.