Teaching someone to quilt is like teaching a pre schooler to write. It is never going to look just like yours. I think they should have complained from the start and ask for a refund or a different teacher. I would have just given up and never went to another class. I get enough critisim in this world without someone expecting me to be a perfect quilter. Keep on keeping on. Your quilts will be yours no matter how they look to others. My family has a game of trying to find the mistake I always leave in mine. LOL