I think you are all reading much to far into this. Its random... I think you all should understand that there is a .01 chance for bats to drop... They are suppose to be uber rare and just because you dont have them doesn't mean we are dealing with a flawed system. Just means you need to keep at it. I am sure that if you would've kept running missions with your higher lvl characters instead of buying new ones you would have been received the same drops at some point. Keep at it and good luck to all of you.