He needs to file for contempt immediately. Sanctions for her could involve lowing the house to him (if he can convince the mortgage company to hold off) being required to pay him for the damage to his credit, or going to jail. Different states have different requirements for how to initiate th e process if jail is going to be an option, most require personal service of process rather than service by mail, for example, so do the resaerch to make certain you've filed properly in case the judge finds this stuff she's done to be so outrageous as to justify jail time.

Don't expect it, though. It's rarely used as a remedy for contempt, but if she knows that it's a possibility, maybe she'll find a way to make the payments current and get him off the mortgage sooner so that he doesn't have to do this repeatedly.