I either lost or didn't get a receipt at Menards for some fans.  I was going to take them back and went nuts trying to find the receipts.  Finally decided that they didn't give me one. 

I checked my credit card online and found the amount, date and some other information.  I took that along to Menards on the hope that they might be able to find something.  

It turns out you can just put your credit card in a machine at their store and it will show transactions for the past 90 days.  Pick out the one you need and it prints out.  Now you can return the item with a receipt.  

I don't know if any other business besides Home Depot and Menards have this capability but it's worth checking.