Xiaomi India - Did not receive the refund

I cancelled a handset worth ***** INR from mi.com the very next day of ordering. They gave me the Transaction Id ************ and told me that the refund was initiated on **-Aug-**** for order id ****************. I contacted the bank where I was told that there is no such transaction in process. Further the customer care provided me with the ARN number ************ and asked me to give it to the bank to track the transaction for which the bank stated that "ARN number is showing that the amount is successfully deposited to the merchant's account but there is no trace of any refund initiation".
I contacted the customer care several times meanwhile but every time they only repeated the same sentence that refund has been initiated from our side, you have to contact the bank for the same. They registered several complaints of mine and assured me that I will receive a call from backend team in next ** hrs but no call came from there side and when I call for the update every time they told me that the complaint has been closed as refund has already been initiated and you have to coordinate with your bank.
I even wrote several mails attaching the passbook photos to prove that I didn’t receive any refund as asked, to which they registered my complaint, escalated the issue, and reverted with the statement that you will get a call but I got a call only once and that too just after asking about what the bank manager said, she hanged up the call asking for * min and didn’t give any callback after that and even incoming is blocked so I was'nt able to follow up. Some of the complaint numbers to my issue are: WOIN*************, WOIN*************, WOIN*************, WOIN************* and many more.
One of the senior supervisor advised me to contact Google pay as transaction was done from there and it has happened to several customers, but I don't understand what they have to do with it as refund is always sent directly to the account from where the transaction was made, instead I did that too but of no use. After that they told me to raise a charge back request from the bank, for which the bank manager clearly said that "the bank is not liable for this as the transaction is not at all disputable and the amount is successfully credited to the merchant's account. The transaction issue is from the side of company so they are liable for the same until they show the clear proof of transaction as the bank have their own policies". The company is not even to ready to provide me the proof also. It's been almost four months and yet I have not got my money back. Each and everyone is blaming the other for this. If they initiated the refund and the bank is unable to track the initiation and saying clearly that no refund is initiated from the company for the ARN number, then where is my money gone? In some reply mails the transaction date mentioned is ** Aug and some mails say ** Sep and in between I got a call from the company on ** Oct after I sent a notice after the consumer complaint where the personnel told me that there was some system issue due to which refund was not successful but we have re-initiated it today and you will get it in *-** working days but after few days I got to know it was a lie and since then there is no proper resolution to my problems. Please help me getting my money back.