Ibibo Group / Goibibo — Flite date change

We have booked our flite from goibibo on 28th Nov from Kochi to New Delhi. By mistake we booked flite for 16th of January inspite of 17th January. We contacted Goibibo customer care for the change because we were not given any option to change it in our app. there was an error occuring. After contacting we also paid extra charges for date change near about Rs. 3200/-. our ticket was raised but not resolved. we are continuously taking follow ups but no satisfactory response is being provided by goibibo. Now even the flite cancellation option is not showing in the app. we have paid extra money for our modification but neither our filte date has been changed nor we have received any refund. we are facing too much trouble from 2-3 days. we dont know what is to be done now. please take it seriously and resolve our issue.