Wife harassing husband for forgery case

A was with B in a conjugal relationship for 2 years (without the knowledge of her parents)and B has changed her name to BA. She has given affidavit of maariage. She also changed her address to A's addressing him as her husband In her voter ID, PAN card, AADHAR. She also held a bank account as A's wife till now. due to some unknown reasons(intention to marry someone?) she is alleging that all the documents were forged by A. She has also filed complaint (Not FIR) in SP office that A is harassing her , when A tried to communicate for goodwill. A sent those documents to her parents and then again she filed complaint that he's continuing to harass. though none of documents were forged , she accuses him of it. he's the proposer for her bank account. she now is trying to revert the changes in those documents without my notice, She has sent middle man asking A to write and give nothing happened between them and all documents were created by 3rd person. Suggest how to defend legally