Receipt checking required?

I shop at Walmart occasionally and absolutely hate when they ask to check my receipt at the door when I'm leaving. It's not like I have a membership or anything like at Costco, am I required to let them check my receipt at Walmart or can I decline and keep walking out the door? Don't want to get in trouble but it is just such a huge pet peeve to have to pull out my wallet again or stand and wait for the stupid text message receipt. What do you all think?