admin exam question

Asked a few days ago, but maybe it was in the wrong topic area. I have been trying to take the admin test for a few weeks, it kept telling me I wasn't eligible. Then the other day, it finally said you have already taken the exam once, retake is against the rules..

Anyway to fix this as I have yet to take this exam, and wanted to try to become an admin. If I bomb out on the test, I still would like to take it regardless. I consider myself to be able enough to look up the rulings that of which I do not know