Congratulations on getting the Massachusetts Attorney General's office on your side, because that office is very busy and overwhelmed and must by definition severely limit those cases which it chooses to pursue. So, that you have gotten that agency to take on your case is a major accomplishment. I know it is no solace to you but you must simply wait until your hearing date. Many others have had issues similar to yours and have not gotten as far as you have and so you are ahead.
In my practice, when clients report that employers have not paid them the wages that they are due, I refer them to the Massachusetts Labor Department. There is a division within that department that enforces the wage-hour laws and my clients have called me back and reported success.
I recommend that you call your contact at the Attorney General's office and ask if also going through the Labor Department would conflict in any way with the AG's efforts. If not, I highly recommend that you pursue that avenue.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.