I had this happen one time with top quality LQS fabric. I cut the large squares and then starched and pressed. The fabric shrunk over 1/2" and didn't even shrink evenly around, just got all wacky. It was 100% cotton too. The shop was too far away to return the fabric so I washed it in hot water, ironed it dry and used it for small projects. I did contact the shop and was told no one else had complained about it. I wonder how many quilters were so frustrated thinking they were cutting wrong.