Your admin rights were, according to the User Rings Log, never changed. Which pages are you trying to use your admin power on? Did you get a "permission required" message or something? That sometimes happens but another attempt should solve it.
Looks like you were never an admin on that wiki...what evidence do you have that you were? You never have appeared to edit a MediaWiki page which is the best kind of evidence that you were an admin at some point.