GoAir — they have charged twice for my child

Sir madam

I shailaj diwakar travelling with goair delhi g8 153 flight on 19 aug 2017. My daughter was also travelling with me (She is infant). She was carrying a ticket with my mother whose pnr num was kbqqgy. My concern is that go air people charged it again saying that she was joint with my ac. My pnr num is j3zsz6.
Now my daughter whose only tax is payable they charged me twice.
Is it fair
They haven't given me two ticket also.
The go air domestic delhi 1d terminal staff are very much rude and useless.

Thanks and regards

Shailaj diwakar\[protected]