When you came to know about her extra marital relationship with a third person, you cold have asked her option to continue with this life with you or to get separated from you, this would have save your prestige as well as humiliations. Instead, despite she asking for divorce you remained adamant about not to give divorce to her, the reasons you only know it better.
In my opinion, even now it is not late, to avoid further insults and humiliations, it would be better to give your consent for mutual divorce to her and snap all your ties with her. If you are not doing this, you will end up with never ending problems. Even if you dont give your consent for mutual divorce, she can file a divorce case along with other criminal cases, also no law can force her to live with you against her wishes.