or by returning them to the supplier.
You know, we rarely ever do that. Partly it's just my boss and her quirks. But there are also real obstacles to dealing with the paperwork (for our company) to get something returned and the money reimbursed. So that would be another area a Big Boss could improve, if they discovered this was a problem.
Also some items if you order a gross of widgets you can only return a gross of widgets, So you need to order more widgets to make a gross pay any delivery fees and small order premiums and then send a gross back often at your expense, within the allowed return time frame. That doesn't address the possible only an unopened gross of widgets is returnable.
First of all, I've done this, but luckily with office supplies, they don't "go bad." I'm still working on the "12" (i.e., 12 dozen packages - 144 pads, of post-its I ordered 15 or more years ago. Also, I have several boxes of clips in my closet from a similar mistake. If they get in the way, we have an informal admin support network here that usually finds homes for any unwanted office supplies. Although I work for a very large organization (a hospital), each department is responsible for ordering its own office supplies within budgetary constraints. I have full authority to order what I want, provided I don't go over-budget.
If I receive the wrong item, even if I was the one that ordered it, our office supply dealer tells me just to keep it and they issue a credit. If it comes from the internal storeroom, they will take it back, i.e., I ordered what I thought was one box of 100 straws for our conference room, and got a case. I sent back all but one.
It's a fine line to walk - giving your employees what they need to do their work, without giving people carte blanche to waste supplies, and balancing using the office manager's time wisely with the potential supply loss from no supervision. A hybrid approach was suggested upthread - free access to cheap stuff (pens, paper, paper clips), with more regulated access to other items, like toner, calculators, staplers, etc.