For account & billing concerns, it may be more effective to get help from our Billing team. You can contact them here: support.roku.com/contactus then choose 'Questions about my account or billing' on the drop-down menu. They are the best ones to help you out with that matter.
First thing - To prevent this incident from repeating in the future, log into your account at https://my.roku.com and create or reset a PIN value. You can then choose when the PIN is to be required, such as before it will allow any subscription or purchase to be made on your account.
With that out of the way, you may have some success getting this refunded, but don't necessarily count on it.
Note that with most (all?) subscriptions you pre-pay (or obtain a temporary free trial) for a defined subscription period which then auto-renew when the subscription (or trial) periods expire. When you unsubscribe it stops the auto-renewal but the current subscription stays active until the prepaid subscription period runs out. Few, if any, will cancel immediately and refund the unused portion of your prepaid subscription. This is all explained in the conditions shown when entering into the subscription (you know, all that stuff we all agree to without actually reading).
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Streaming Stick 4K+ 3821 | Streaming Stick+ 3810 | TCL Roku TV 43S245/C107X