I bought a female marble from Spencer a week before halloween. just a small wildcaught pup (looked just like the one you got) and within three months she has tripled or more in size on earthworms and shrimp. very happy with my purchase. I've heard those white patches are due to high nitrate and require large daily water changes to reverse the spread.
it's really hard for me to buy a fish sight unseen, but I've only heard good things about Spencer and decided to try him out. got other fish ordered from him aswell and they all arrived in good shape. I suppose they are very fragile creatures and shipping could have stressed her out as well as a number of factors.