No, I had 631 credits. And in the first PM that the admin (the username of the admin is Admin) gave me telling me that I received payment, he said I was rewarded 504 credits, and my credits was deducted 504 (from 631 to 127). And I sent PM to IEarn, asking about it. Anyway, IEarn has answered my question. He said that I went off-topic. Just as I thought. Sometimes I am not aware that I go off-topic :P I better be careful now.
I think this information is useful to all other members as well including me. That means the admin is really checking all of our posts, so we must be careful and not to stray away from the topic. Let's always try to stick to the topic. Anyway, it's just 4 credits, so you don't need to worry.

About the first "credit awarded message", it's an automated message which we receive if our credits get deducted for any reason.