I've heard that JoAnns online is different from the box stores and box stores don't take fabric back when ordered online.. I have no experience in this personally but would certainly call JoAnns (where you ordered) and see if they would exchange it for you.
That said, you could starch the fabric (which would take the puffiness out) and still use it for quilting. It is a soft and lovely fabric but don't know if it would keep the puffiness out after washing. Personally I think it would make a darling quilt...sometimes mistakes are the mother of invention. You might find it would be fluffy in the areas you used it and then with regular cotton would enhance the entire look of your quilt. People mix Minkee and cotton all the time and come up with some outstanding results.
If you sew there are numerous possibilities for it as Dreamer wrote.
Whatever you decide please don't fret over a mistake...life is just too short for that sort of thinking. Have fun with whatever you decide.