Paytm Business - Refund credited back to customer

We have received the sum of Rs.*** on *st April **** at *:** by using the QR code from our customers at our shop. We got a message from paytm that money received Rs.*** but we actually found that our bank had not received the money yet. So I called merchant helpline number and they asked us to download paytm business. As said we downloaded it. When we saw the amount transferred is showing we relaxed a bit, then on clicking on Rs.*** a page opened where a button was available named as "Initiate Refund" and By mistake, we've successfully refunded the amount of Rs.*** received, back to the customer. Now, we don't have any details of the customer to contact him again as the ** digits mobile number is partially shown I.e **xxxx**** to us in a statement. (Except the Recordings through the camera in our shop: Face is clearly shown)
Thus, requesting Paytm to refund back Rs. ***/- to us again or give us their details for contacting them or Paytm should contact them for the issue or give their Aadhar number or pan card number which were used for full KYC to address them and complain. Need Paytm help because there is no bank involved in it as the amount is sent from Paytm Wallet to our QR Code
More information about the issue. 
Order Id of received Rs.***/- : 
******************
Refund id of Rs. ***/- :
***********************************
Screenshots have been attached giving order id, Txn Id, reference Id, refund Id. etc for reference.