Ola Cabs / Ani Technologies — Paid in Cash but Ola charges in Postpaid bill too

I paid to the driver in cash Rs.2119 as he demanded cash payment . But later OLA bills me through postpaid charge too. It became twice charging for the same single trip. Even though i complained to OLA about the wrong billing they are refusing to revoke the postpaid billing. I contacted the driver and asked him to refund my cash payment, he declined to do so . but he accepted taking cash payment. i sent the voice recording ( in Tamil ) to Ola team but they refused it and still force me to pay again. They did not even bother to put the driver in call for confirmation.

I attached the postpaid bill created . but i could not attach the voice recording as the format ( .amr ) is not supported to attach. i can send through email if needed.