It depends how long it has been since the txn, I forgot to mention that.
Basically chargeback is a challenge that can be won or lost but if you provide sufficient proof of wrongdoing, communication, INGRAM complaint, the issuer (the bank) can rule it in your favour.
Merchant will have to generate counter proofs.
So you are forcing the merchant to now advocate themselves against the bank and not just screw the customer over.
In India, chargebacks are still not the one stop solution, in US etc, chargebacks are so powerful that merchants generally give in and hence, are quite often misused.