I think I'd write a letter and send copies of it to local quilt shops, better business bureau in that area and send a copy to HER with a notation on the bottom that letters had been sent to such and such places. I'd also post something on her website if she has one. People who are looking for someone to quilt their quilts, need to know. Mistakes can happen but she should have been woman enough to tell you about it instead of trying to ignore it. And she should have offered to fix it if possible or given you a discount. Personally, if I messed up someone's quilt, I'd be too ashamed to charge them labor or quilting fees on it.