School is Refusing to issue TC

Dear Lawyers, My son was studying in Kohinoor American school, Khandala in Grade 9 last academic year and on April 1st, 2020 school had announced that they are not going to operate from the current academic year 2020-21. Now due to this we have taken the admission in the school in Pune and he started online classes for his grade 10. As this announcement was during the covid situation we did not ask for the TC and other documents. In the month of May Kohinoor announced that they are going to operate but we are not having any confidence in Kohinoor's management and do not want to change the school. Because of the family medical issue followed by Covid situation we have outstanding fees of Rs. 3.9 L with Kohinoor, when we asked for the TC they replied that they will not issue the TC as the fees is pending as well as we took the admission in the other school while their school is running. Also they had sent a mail to new school defaming us about the non payment of the fees. What are the option for me in this situation as Grade 10 is an important year in the child's career. Please advice. regards Chirag Shah