Dglvr...I am so sorry to hear about the difficulty you are having. I have never had that type of problem with batiks and I use fusibles with them frequently, without even prewashing the fabric. I don't know what brands Joann would carry. I use Island Batik, and Hoffman primarily. I did have a problem with one brand of fusible? What brand of fusible are you using, could that be it? I use Lite Steam a Seam with good results.
Have you tried pressing longer or hotter?