sorry, lenders operate under the principal that states do not default and do we really want them to operate otherwise?
If not GS then the IMF or some other organization would have been coerced to loan Greece money. Greece has been betting on the idea that the EU could not afford and would not allow them to implode.
When they got called on it they went into blackmail mode. Worse they set up a force failure by locking down bank transfers for the week. This means no one can do business, you cannot pay for what is being shipped and cannot place orders for more. Why would any EU company trust a Greek purchaser to pay now?
What must really happen is Greece must right size their government, pensions, employees, and military, to what they can afford and quit pretending its evil mean bankers that caused their plight. Oh they might have helped by lending money but Greece never would put forth serious effort to constrain spending.
The austerity the claim to suffer is applied the same way all politicians apply political pressure. By depriving those who already have no voice of essential services while making sure they themselves, their cronies, and supporters, don't suffer or as much.