I agree with lowjane and grammysharon, fuse the area and then stitch to secure then -applique over the problem.
At Sew and Tell, a guild member explained how she "embellished" over an area where she made a mistake.
The area had huge pleats quilted so she appliqued over it with a Star vs. tearing out the stitches. She then added a few more stars of different sizes.
The stars on the quilt were a big hit. I hope this helps you with your quilt.