Indigo Airlines — Money debited from my account but ticket was not booked.

Address: New Delhi, Delhi

I booked a ticket from Delhi to Kolkata for 1st July, 2015 ( Ref : X58I6F) on 1st June, 2015 by paying Rs 3297. On 23rd June, I tried to modify that ticket and reschedule to 13th July. The balance payment of Rs 3492 was debited from my account but the ticket was not modified. ( Please refer my transaction through netbanking of Allahabad Bank, Transaction no. 32567). On contacting Indigo customer care executive, I was told that the booking made on 1st June was a promotional offer and therefore it could not be modified. Then after some time I spoke to another customer care executive, who advised me to use debit card instead of netbanking. I tried but failed to modify the ticket. Then, again, I contacted your customer care executive, who said exactly what the first person said ( It could not be modified) and assured me that the amount debited would be refunded back within 3-5 days. So, far the refund has not been effected. Please ensure the refund of Rs 3492, which was debited from my account at the earliest.