She should not have charged you a penny for this mess she made. I can understand if you bought the batting from her, but that's it. I know this sounds daunting, but I would take out all of the stitches and start new with a new longarm quilter. I've been a longarm quilter for 7 years and have taken out stitches on many quilts during this time. If you do go this route, I would lay the quilt on a table, pop the top threads, about every 1/2" apart, and then the bobbin threads should pull out easily. Put on some music or book on tape and the time will go by.