Since you have accumulated 5M diamonds, you obviously knew what you were doing and how to achieve such a result. If it was on a single occasion- ok, it happened by accident and it was not your intention.
You also should have reported it (via a PM), since this is a really serious matter. Creating diamonds or resources out of thin air ruins the ballance of the game and spoils the auction system. And this is Beta- the place where the team observes how certain changes wil affect the realms behaviour, which will make the game more or less ballanced. And what xenobalance do you expect to find, when you exploit a bug and spread the news to other players, thus creating even more chaos, instead of directly reporting it?
P.S: Commoner gave an example about the abnormal behaviour of the auction.