Do you want to change your Tiimo subscription plan? Don't worry that's of course possible, but the way to do it depends if you're on Android or iOS.
On iOS You can can change your Tiimo subscription to another subscription plan by logging into your Tiimo account on your iPhone or iPad.
Go to me > then manage subscription > press manage in the question box > find the Tiimo app and choose your new subscription.
On Android it's not possible to change your subscription plan in the Play store so you will have to unsubscribe from your current plan, see here how that is done, and then subscribe agin the the new plan.