What is the condition for a Lifetime buyback policy for gold?

LTB is applicable after 15 days from purchase, upto 5 yearsBuyback will be calculated based on:1.Gold value at prevailing market rate2.Diamond value:  : 90% of the prevailing diamond value or 90% of the Invoice value - whichever is higher3.Making charges, GST, promo coins deducted4. Processing fee of 15% is applied"