i had that problem several years ago. after multiple requests for help, waiting over a half hour for someone to cut fabric, i cut my own, brought the cut piece and the bolt to the regiser. then the front end folks went nuts! i wasn't supposed to do that! they were very busy at the time - no excuse for ignoring me if fabric dept - and finally decided to check me out at the register. Then the clerk asked why I wasn't taking the bolt. I told her I didn't buy the bolt, just the 2 yard piece she checked out.
This is always a problem at walmart, so I don't fabric shop there nearly as much as i used to.