Could the batik fabric be rayon instead of cotton? I have seen a few places selling rayon batiks and rayon can really fray. If the store won't do anything about your problem; or, if you love the fabric colours and really want to use it, my advice is starch, starch, starch. Also, if you can, make your seams a little more than 1/4". Possibly, you may have to zig-zag them if you plan to wash the quilt. Lastly, I would quilt the finished project very closely. Hope things work out.