Air India — online ticket booking

I tried to book an international flight ticket on air india website on 17th february 2020. Payment was done and no ticket or ticket details was generated. When i called the customer care center they given a pnr number against that transaction. My bank has confirmed that the transaction has been executed properly and the money has been registered with the merchant on 19th february 2020. I have been trying to raise this complaint through air india ecommerce, but unfortunately they told it was an error while transacting through their website and their account was not credited, and the debited money will be refunded in 6-7 days by the bank. But it has been 3 months now, i haven't received any refund.