Qatar Airways — Refund for double transaction

I booked an air ticket with Qatar airways on 23rd May. The first transaction failed but the amount has been debited from the account. But I didn’t get any mail or messages for the failed transaction. The second transaction was successful and got the ticket. When I contacted the Qatar airways customer care they said they have only received one payment (ie second) and told me to contact the bank. When I contacted the bank they asking for email from Qatar Airways stating that the transaction was failure. It’s been almost 1 month I haven’t get any mail from Qatar airways after many calls and emails.