First of all, the entire 100 was not me, that was between me and some other guy on here that you were talking to.  You sent me 50 Euros and received a total of around $40 in BTC.  The last part of the transaction was for the majority of the amount that you sent me and you sent a message just before that transaction stating that the amount was fine.  I am sorry that the other guy has screwed you, but that has nothing to do with me and should not be put on me.  Check your records and stop trying to scam extra cash out of people.