I filed bankruptcy, it was discharged. Then SSI demanded payment for 30k that was from 2009 but not asked for until 2011. I filed my bankruptcy in2010

With out knowing more, I'd have to guess that your case was a no-asset chapter 7 case. Case law in Georgia has established that there is no need to reopen a no-asset chapter 7 case to add an omitted creditor. As a no-asset case, there was nothing for the creditors to get, therefore it serves no purpose to add them. Your unlisted debt is also discharged. The SSI overpayments have no special protection under the Bankruptcy code and therefore your debt should be discharged. SSI may try to argue that the debt was incurred after your discharge, which would put you back on the hook for the money. However, the facts as you present indicate that the debt was incurred pre-filing. SSI may even try to reopen the case to fight the dischargability of your debt.  I've made several assumptions so if any of them are wrong, you need to just throw out this answer. Either way, you need to hire an attorney that will make clear to SSI that their debt was discharged, with or without notice.