GST on flat sold after completion certificate

mahan (self) (85 Points)

31 May 2024  

Builder Developer insists on GST payment by buyer on flat being sold after completion certificate, even though GST is not applicable on sale after completion certificate.

Whether builder can give GST invoice or receipt showing GST, for flat sold after completion certificate?

How to do the deal? 

or

how to complain?, to whom to complain ?

or

how to get refund of GST so paid?