In the USA for many of the mortgages made from 2003-2007 the banks may not be able to find the original sales contracts and other documents which were done by fly-by-night "mortgage broker" boiler room operations. If you don't need to move, ceasing payments and staying put is a good bet. Meanwhile, save as much of the payment as possible to prepare for what ever is next.

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."