Payment due for 1 and half years.

Bahubali Cv (19 Points)

12 July 2020  
We had generated a bill with GST invoice two years back(in2018). But the payment is due. Now, the customer is insisting to give a new bill (dated 2020) as he is not able to avail tax portion for the old bill.
Can we generate the new bill?? And what to do with the old bill?
please suggest