Reliance Retail — Amount Debited twice from my Card and not yet reversed!

My card was debited twice for the same amount and the amount has not been reversed in my bank account yet. What is the reason for this delay? Transaction Details of my purchase: Date: 17/05/15 Time 17:52 MID:02M[protected] TID:00668452 Amount: 1000.54 The failed amount was previous one with the same amount.