Hint App Won’t Let Me Cancel an Unwanted Recurring Subscription

I am writing regarding an issue with the Hint App on my iPhone. Today I discovered a $29.99 subscription on my account that I did not knowingly sign up for, and I have been unable to cancel it through the normal options in the app. I do not want this subscription, and I did not intend to authorize a recurring charge. Since I cannot cancel it myself, I am asking for this subscription to be completely cancelled so that no current or future charges of $29.99 are taken from my account. I request that this subscription be removed immediately and that my account be updated so that it cannot renew again.