Indigo - Asked to cancel the flight they didnt Put it under no show and denied refund

Had my connecting booking GQPE*F today with IndiGo departing at **** hrs. However, I received a call at **:** pm that my flight is delayed. Owing to which my return flight N****U got hampered. I called cust care at *:** pm sharp, then again called around *pm and then *pm. I have been on call for like ** mins, then * mins and then ** mins again just to cancel my booking. However, they told me to wait for senior executive but they didnt called and I waited for almost * hrs. And now Kunal telling that it cant be canceled.
I spoke to them yet again for ** mins but they are not accepting their fault and telling that the flight cannot be canceled. What is IndiGo upto? How are they making revenues? They allegedly put my booking in no show and didnt cancel the ticket