In fact, it is true that no one can take one's luck. But many such events happen in human life which have no explanation.
Yes I feel your pain to have your hard earned money betrayed like this is really sad. But I don't think you cheated but I think you won.
Your sustenance will not be much less than what it was, but what was taken from you will not be found in this world, but you will find it in the field of Hashar. Which will benefit hundreds of millions of times from now.
I will give you a suggestion (trust is good but blind trust is not good) good luck for your competition.