Get them well fed and healthy first. If they feel better physically, they will be a little easier to tame. Then work with them to become social and happy. I'm sure it will take a long time but you don't want them going back to their former "home". I know you get rats to breed, but maybe these can just be considered rescues who you help to have a better life. I am sorry for the loss of money but I would not try to get your money back and return them to that woman