Flirting with a teacher over the phone who is now accusing of cheating

Dear Sir/Ma\\\'am, I was out for a school\'s seminars in some district of eastern state. A lady teacher become my good friend. I just talked with her and after coming back we had whatsapp discussions. I was made enough to talk and discussed her about sex for the time we meet next time but no pictures at all and she replied with a consent (as I was just kidding) which actually never happened and I did not went there again. after few days I stopped texting her as I was busy and now she calls again and again and says I betrayed her/ she is sorry/please call me/ aapne dhokha dia and all.I changed my phone number but I am still feeling horrified. I never ever touched her or promised her something. After that I came to know that She is a divorcee and very elder than me I never ever touched her and I am unmarried. Was it illegal? What shall I do ? Can she take any legal actions against me?