I worked at Wal-Mart for 15 years, and know that they will take back anything that isn't as it should be, and give a refund. I am amazed at how many people don't know this.
I have always had good luck with fabric purchased at Wal-Mart. Our store is the only store with fabric in town. I have not ever had bad luck with any of it, but I do know that customer satisfaction is their goal. I would just take it back and try it out on returning for a refund.