When did you ask for the waiver? I just got a waiver for another client that seems to have been in a similar situation as you are now (DUI several years ago). She had completed all of her probation conditions, taken all the necessary classes and only had the ignition interlock remaining. Of course, every judge is different, but that judge didn't think twice about waiving it for her. If it has been a while and you still believe you meet the requirements for a financial hardship, it may be time to ask for a waiver.
If you had a lawyer on the DUI, give them a call, as they may be willing to help. If not, and if you can't afford one, you might be able to put the case on calendar and talk to the judge yourself for free. However, hiring an attorney will greatly increase the chances of things working out the way you want them to. Good luck.
An Ignition Interlock ORDER is required for installation, if that is what you want to do. In the alternative take my colleques suggestion and hire an Attorney to file a Request For A Waiver.
You should consult an Attorney that handles Traffic cases in the jurisdiction you received the citation to evaluate your options.
Georgia law was recently changed on January 1, 2013, but your exact problem is not resolved in the law. The current Georgia legislature is considering changes to the laws relating to ignition interlock with second offenders, but that change may not help either, and (if it does) the effective date will be between May and January. The $500 cost for an attorney to try to help you get reinstated is a very low fee, IF you get your privileges reinstated. If it does not get resolved, then that is $500 down the drain. You are down to a personal decision about how much longer you are willing to go without the legal right to drive.
Sign up to receive a 3-part series of useful information and legal advice about DUIs.