This method working if you have Basic Elite Card (activated or non-activated - don`t matter).
Based on the transfer of Basic privilege to Elite at a rate of 2 to 1.

Go to Storage >> Boundle Coupon >> Trial Card Item >> Use Item

Your activated Premium Elite Privileges will be extended with rate 2 to 1.
(Example: If you activating 30 days Basic Elite Privileges - its converting to 30 / 2 = 15 days Premium Elite Privileges)

Go to Store >> Elite >> Purchise Premium Elite Privileges
Your activated Basic Elite Privileges upgrading to Premium Elite with rate 2 to 1.
(Example: If you have 30 days Basic Elite Privileges - its conditionally converting to 500 Bonds discount and you need to pay 1000 - 500 = 500 Bonds for activation 30 day Premium Elite)