I bought a big piece of fabric to cover my design wall at my local JoAnn's, several years ago. I had it cut about 8" larger than the board because I wanted to have several inches on each side to pin around to the back. When I got it home, it had been cut so crookedly that there was not enough to cover the board. I took it back and had no problem getting my money refunded, but that store didn't have enough of the fabric (after it had been badly cut) to sell me the size I wanted, so I went to another JoAnn's and got it with no problem.
When the issue is that something you bought is not the size you paid for, I truly believe that your local JoAnn's will have no problem at all in refunding your money, unless you have cut up or washed the fabric. That store should then inform corporate that their FQ shipment was faulty.