MakeMyTrip India — Charged twice for seat selection on flight

I had booked an indigo flight from Goa to bangalore on makemytrip app. And I was charged on the app for the seat selection. While I was about to do the web check in, the flight was a smaller (ATR) and did not have the row which I booked for. And I had to pay the seat selection fee again on indigo website. There is No way to get hold of a makemytrip executive to talk to about this.