I have no idea how many customer service complaints Walmart gets a day, but I'm going to guess it's a number with more zeros than I can count. 

Greg Benson decided to conduct his own retail prank on Walmart and called in posing as a quality assurance monitor from corporate with his friend Plymouth pretending to be a customer on the other line. Greg tells the Walmart customer service rep that he'll be monitoring and coaching her on what to say. As you can probably guess, it doesn't take long for things to go awry. 

She actually handled the whole thing pretty well, and thankfully Greg called back to let her know it was a joke before she did anything drastic like flip in the frozen foods section.