With Walmart, it's pretty difficult to enforce a ban. Management is trying to run a busy store, and they may not be made aware that a banned customer or shoplifter until someone who recognizes or remembers him or her calls it to a manager's attention. Usually, they'll have the loss prevention guys trail him/her from a distance, but if they're in the store just to buy something, and not actively vandalizing anything or trying to shoplift, they won't tell him or her to leave. Otherwise, banned customers probably could walk in, get something, pay for it, leave, and no one in management would even know they had come back.
So, even if Chris thought he was being bold and defiant by returning to the Walmart where he was banned for vandalizing the XBox display and the Magic Mike DVDs, he wasn't. He just happened to go in and get what he needed, and no one in management or security remembered him, or cared that he came back. Yes, Chris sticks out like a sore thumb. But really, management had more pressing concerns than telling the fat, unwashed crossdresser to GTFO.