Paytm Mobile Solutions — delay in refund and ignorance

I ordered a product on paytm on 15th oct 2018 on cash on delievary. At first they provided me the wrong product, thereafter i retured and asked for my refund, then they said me to provide my bank details. I provided them with the same but i didn't get my refund. Then i provided them my paytm payments bank detail and they sent a verification message that my bank has been verified and i'll receive my refund soon. But even about two months of refund initiation i haven't received my refund. Plz help me to get my refund and be strict against such frauds.
Order id - [protected]
Contact no - [protected]
Email - karanmzms.[protected]@yahoo.com