You need to retain an attorney who will review your entire record and then take steps necessary to protect your interests. Here are limits on when you must move forward so hire a lawyer immediately.
I advise you to consult with an attorney. Many attorneys on Avvo offer free consultation. An attorney can investigate your record and act as a liason with PennDOT. Also, it has been my experience that PennDOT does not act with great speed. I believe you could call PennDOT, explain to them what happened and that you were never convicted (according to you) and see what they have to say in terms of removing the suspension of your license.
From your question it sounds as though after you plead not guilty, you appeared before the MDJ and were placed in a pre-adjudication (diversionary) program. Unfortunately, when you were placed in a diversionary program for minor drinking, you are subject to a suspension of your operating privilege under section 1532(d) of the Vehicle Code. You should speak to an experienced lawyer immediately to see if there is a way to either reopen your case before the MDJ (highly doubtful) or file a summary appeal. You may also have to file an appeal from the license suspension which you received. The license appeal will stay (stop) the imposition of the suspension while you try to reopen the summary minor drinking matter. You have 30 days from the mail date on the suspension notice to file a license appeal so act promptly. PennDOT has no discretion in imposing a license suspension in these circumstances and you must successfully attack the underlying minor drinking case if you want to avoid the suspension.