That's true, I just suggested checking it since the OP mentioned the spindle being damaged. I guess;however, he meant the square hole that fits on the spindle was deformed.

Hate to break it to you OP, but if you're looking for cheap parts you may likely expect the same results. At least you were lucky enough to get a full refund, pick any one and go for it. Also, not sure what kind of riding your doing, or your weight (not intending offense) but those could also be major factors in the stress the crank suffers. I personally would shell out a little more to avoid this situation in the future. Sugino RD2 or Messenger cranks are a bit above you're budget but reliable and on the cheaper end of the spectrum for quality.