IGST - Place of supply in DRC - Jurisdiction under 73 - Goods and Services Tax - GST

Proceedings under section 73 was initiated against a person registered in the State of Kerala for reversing ineligible IGST credit. The registered person has already reversed the said credit vide DRC-03 along with interest before SCN. So the said payment was submitted in the reply to SCN. However, now the order has been passed wherein the payment is not allowed as Place of Supply selected in DRC-03 is Haryana and not Kerala . 1. Whether the officer has jurisdiction itself to issue SCN under 73 r.w.s 20 of IGST Act , considering the IGST credit is already reversed? or to put it differently, whether wrong selection of POS be treated as non-payment of IGST? 2. Section 77 / 19 provides for CGST/SGST to IGST and vice versa. However, no mechanism prescribed to change PoS in DRC-03 . So whether refund to be applied and payment to be made again? if so whether interest and penalty to be paid?