For the 6-month premium, your Subscription account will automatically cancel once the expiry is up.
For users who are unable to join the premium account even after keying in the promo code, they could already be subscribed to the premium account as they had joined our past event (i.e. Sports for Life Million Steps Challenge 2021 Season 2). Once their current subscription account expires, they should be able to key in the new promo code and reactivate their free 6-month premium account again.
This is how it will look on your phone after 6-month premium has expired:
