Sbi Credit Card Department - SBI credit card double billing

i had purchased inalsa inox **** food processor from flipkart on **-**-****. for online transaction i used sbi credit card for payment rs ****/-.
while payment process my transaction failed, so i tried another time for payment. this second attempt was successful.
sbi credit card detected twice in my billing both failed and success transactions are billed.
i filled complaint in flipkart website. they called and said problem with sbi credit card department so inform to sbi.
i filled complaint in sbi credit card website. they revert my amount rs ****/- by credit amount in my account. by informing it will take *** days to investigate.
after *** days they inform that " we had taken up the matter with the merchant bank process credit for said transaction. in response to which, the merchant bank had provided us with a copy of the charge slip/document for rs ****/-."
by stating above statement sbi revert amount rs ****/- by debit in december **** statement.
actually i complaint about double billing but sbi investigated for transaction dispute.
i inform so many times to sbi complaint about double billing on my card. but sbi not considering as double billing.