Legal Question in Personal Injury in California

It is very complicated to stop a foreclosure sale [if that is what you mean], there are no "forms". you need to read prior answers to similar questions on this cite, and you probably need to hire an attorney.

Illegal? You mean you made all the payments and they still want to foreclose? Don't file forms. Consult an attorney right away. Don't wait. Foreclosure sales are fairly easy to stop in advance, but nearly impossible to reverse.

It depends on what is illegal about it, and chances are there are no standard forms, unless the proper way to stop the particular sale would be a bankruptcy. Otherwise you would need a lawyer to draft the proper pleadings.