420 case if woman refuses marriage after date fixed for wedding

Dear Sir/Madam I was engaged to a women for almost 20 Months. It was family arranged engagement which turned to be a love affair almost. last year in October my mum suddenly died of cancer. after that a quick ring ceremony was arranged and wedding was decided in December. but just 4-5 days after wedding gal started blaming that some one told her that i am married and i have kids. where as i am single without kids. then she broke up. in the period since we were engaged she took some gifts also from me, such as new galaxy mobile etc. Also she used me a lot do her official computer work through internet that used to consume almost 10 Hours a week. even many letters were written for her by me for her official correspondence even i think some of her senior official was also talking to her a lot on phone, even late night. it might be that she was involved with her as she often used to go to Delhi often (organisation head office is in delhi) but i dont have any proof of their any involvement of affair except some outgoing call details from gals mobile to that official's mobile. can i file any cheating case or defamation case against the woman?? Greets