First, it is absolutely essential that you be truthful and hones. When you were denied entry were you allowed to withdraw your application or were you subjected to expedited removal? The answer to this question is going to determine your fate. You need to get copies of all the documentation from the time you were denied entry and discuss your case with an immigration attorney. The consulate already knows what happened. They are just waiting to see if you are going to disclose it and if not charge you with being inadmissible for fraud. There are waivers availble to you but those are often difficult to obtain and time consuming.