Airtel — international roaming double top up

My number is [protected], i am in singapore and on international roaming, i had activated internationa roaming 2498 plan on my number. I had tried doing it on 20th jan and i received the information that the transaction failed, therefore i did it again on 21th jan. On recieving my credit card statement i realized that both transaction was through. I request you to transfer on of my services to the next month