Last year we opened a forum topic for people who had experienced the Experience and Credits glitches to report what their original rank and cash amounts were. For all of the people who responded to that thread we restored their accounts to what it was before the bug gave them lots of rank and cash. The forum message was open for over three months and we posted multiple announcements about when it was going to be closed and what would happen to players who did not post there.
There were hundreds of accounts affected, and about 30 accounts who replied to the forum request.
You did not post in that thread, and your account did suffer from the glitch to gain unfair rank and cash. Although the glitch is not your fault (it was a bug or vulnerability in the original release of the game), we had no choice but to reduce everyone who gained and did not respond to our request to a standard level and equipment.
I hope this answers your questions about why your rank and items were reduced.