This is the reply I got when I email their customer service.
Thank you for contacting kmart.com.
We appreciate you shopping at kmart.com.
The Summer Breaks sale prices may not apply to certain sizes, styles, and
colors. However, if the item clearly should be offered at the sale price,
go ahead and place the order. If the sale price is not applied, contact
us after the order is submitted, and we will adjust the price if the sale
price should have been applied. Please check to make sure you have
selected a sale item.
We apologize for any confusion.
Look for great bargains throughout the store and find Kmart exclusive
brands like Martha Stewart Everyday, Thalia Sodi, Joe Boxer, Route 66 and
Kmart Customer Care