How to deny Maintenance in fraud case

i was married 6 months back. i am having a little problem in my leg. the girl also has some problem in feet. but after marriage i discovered that she has multiple problems and a disease called Myelomeningocele by birth its a uncurable and severe disease. my in laws tried to threat me. aftre 20 days the girls returned to her parents home on the pretext of her exams. but she filed annulment case against me on the false basis of impotency. she also filed false complaint under 498. now she filed maintenance case under 125. please tell me how can i deny maintenance. fraud is committed to me. i am a govt. emp. earrning 16000/- pm. she is also MSc.(It) and was working before marriage.she has stated her working in case. the marriage is not consumated beacuse of her disease. please tell me where i stand in the case. i also want annulment now.