Hey, This is Ziggy from White Clay. You were contacted by a SCAMMER. DO NOT deposit the check, DO NOT buy the gift cards at Walmart.
I'm really sorry they're attempting to victimize you. As others have posted, they hide behind the names of legitimate shopping companies to fool people.
If you'd like to sign up with a legitimate firm and ACTUALLY get paid for your work, we have a shopper FAQ site at www.wcshoppers.com. Cheers!