I am not a super experienced quilter by any means, but I have an idea. If the quilt is really not able to be redone because you trimmed it, could you run an invisible stitch down the pucker lines so they at least lay flat? I don't know if that makes sense. To me, the folds remind me of sewing binding on to a project. It seems like you could tame them, if there isn't another solution. Sorry this happened to you. I'd be really disappointed.