I think I only tried doing a price adjustment once upon a time, @sonofzeus , but didn’t follow through because the xx% coupon on the original purchase was no longer in force when the sale price kicked in a few days later, so it would have been a loss or a wash to continue with the adjustment.
I don’t see anything in Kohl’s online FAQ section, but this is what the rules were ca. 8 years ago:
Price Adjustment - If you purchase a non-clearance item and it goes on sale within two weeks of your purchase, you may ask Kohl’s to honor the lower price and make a price adjustment for you (return the purchase and re-purchase it at the lower price).
Note: if your original purchase received Kohl’s Cash or a discount that subsequently expired, you may not get either benefit again. YMMV
Accordingly, I would expect that the $20 off $100 would not be accepted during an adjustment, since the code would have expired.
If there’s something that you have already purchased and now it’s on sale and you have a $20 off $100 code, I would just purchase the exact same item and just return the item from the first purchase.