Company not refunding GST for returned goods. (Returned post 6 months of purchase)

Bought an electronic item in March 2025. Multiple issues, they delayed refund and finally processed the refund after 10 months post purchase in Jan 2026. Got the invoice amount back without the GST. Is this normal? Will I not get the GST back?

If I am supposed to get the GST back but they are scamming me, could someone please guide me towards the exact act/law which I can show to the concerned company?

Asked in r/IndiaTax buy didn't get any response so far hence posting here.