What to do if someone is harassing me for money?

I want to file a complaint against person who has lend money to my husband, Reason is even after taking interest every month and also giving assurance of paying the full amount. She has been harassing me by sending massages and calls to my relatives saying we took money from her, she is now threating that she will lodge fraud case on us, Saying we took money and not returning she sent this massage to all relatives. This is peaks to my patience since after paying her 50k interest every month, I ended up facing thrash and my identity is being ruined in family. I need advise if I can file a complaint on her, and I also want to stop this interest and just pay her the principal amount in stipulated months not at once.