Billdesk — While paying electricity bill, the money got deducted from my bank account twice

While I was paying the electricity bill online(AP state), the screen showed error. So I reentered my debit card details to make the payment again after which it said payment successful. When I checked my messages, payment was made twice and double the money got deducted from my bank account. Kindly fix this problem and return the amount in excess of the given bill.