I am so sorry for the tragic loss of your London. Shame, shame on that breeder for letting that tiny puppy go at only ten weeks.
Florida has some of the toughest "puppy lemon laws" in the country. It doesn't matter what your breeder's contract said. She did business in Florida and must abide by their rules.
Since London died with 14 days of her sale, you are entitled to a full refund. If a necropsy had been done and she died from a congenital condition, that guarantee would have extended to a year.
The law with a link to a complaint form is here:
Pet Law, Division of Animal Industry - FDACS