Gree/Deca exchanges supply drops to stamina with ratio 3:1 (). When both stamina and supply drop have the same cost of 25 gold bricks.
1. This means that hardcore boss event finally destroyed and cancelled.
2. If you bought supply drops with gold in long time ago, you can exchange them for useless stamina only now.
Supply drops must be exchanged to gold.
And this must be performed automatically for all players/accounts. There is no any need in any request form.