You do have my sympathy as well. But look at the bright side, you have learned a valuable lesson about testing and pre-washing. I would also suggest finding a different source for fabric for all your wonderful projects in the future. I am not a fan of the quality of JoAnn's products. Like you I learned the hard way as well. Made a beautiful hand quilted sampler that faded horribly (with very little use as it is in a guest room) as well as the fabric literally coming apart in places. Additionally, I have read numerous horror stories here about their flannels. I prefer to only use them for notions, tools and specialty items like fusible interfacing. You can get wonderful flannels and quilt shop quality fabrics on line for a fraction of the price JA charges. Try
www.thousandsofbolts.com. And for Synthropol, which you may have difficulty finding in your area, I highly recommend Dharma Trading Co.
http://www.dharmatrading.com/topnav/chemicals/