As stated  by sid2010, the best idea is to contact the bank by e-mail and tell them the story. They will sure prefer their recovery than to put you in jail. Even if they will send you to the jail, there is no use, you dont have money and the court cannot force you to pay if you dont have any source.

It is sure they will agree to get some guaranteer and let you pay the money as soon as possible.

But the most important is if they already filed a case then I really dont know what they will do, so this is the only solution to contact them by mail. Good luck