BEWARE! Big Lots Has A No Return Policy Without A Receipt. So If You Get A Gift, Please Include The Receipt In With The Gift Or They Can't Return It. Unlike Pricey Stores Like Kohls, Belk, And Macys, Big Lots Stores Have "Golden Rules." Why?

The decision was made at the corporate level.
Not sure of the exact reasons.
It has to do with several reasons in my opinion:
     Abuse of the previously open return policy.
     Theft by associates
     Markdown Dollars (Margin Loss)
     (Unlike most retailers  that get credit on most things from the manufactures - Big Lots can not get credit for things and has to either sell the item(s) at a discount or zero it out of inventory.
MOS (marking out of stock) items has a impact on the gross margin and these costs need to be past on to the customer.  By reducing markdowns from returns everyone saves money
The Markdowns from returns were quite expensive for stores. Saving a "point" here and there adds up.