When you start a 7-day trial, you get access to all Elevate games and features free for 7 days.
After the free trial period, your account will auto-renew into an annual subscription and you will be charged.
If you do not wish to enter into a subscription you will need to turn off auto-renewal at least 24 hours before the 7th day, as both Apple and Google start to withdraw the funds for a purchase 24 hours before a trial renews.