Sorry, but no refund is possible in this case. If you do not cancel your Boosteroid subscription, it will be renewed automatically. If you don't want to renew your subscription, you should cancel it.
Here's an example: On January 1 - you buy a monthly subscription. It will be automatically renewed on February 1 and its price will be charged from your bank account. If you don't want to renew your subscription, you should cancel it before February 1. We recommend canceling the subscription at least a day before the rebill so you simply don't forget to do that. Moreover, you can cancel it even the same day you buy it (on January 1). Regardless of when you cancel it, you'll still have access to games till February 1, but on February 1 your subscription will not be renewed and you will not be charged.