Scout subscriptions are bought in the app through Google Play. The plan, price and any trial are shown on the Google Play purchase screen, and the purchase has to be confirmed with your Google account before anything is charged. Google emails you a receipt.
Your plan auto-renews unless you cancel in Google Play (see How to cancel your subscription). Someone else using your phone or Google account? Turn on purchase authentication in Google Play → Settings → Authentication. If a charge still looks wrong, contact support@searchscout.app before disputing with your bank — we can almost always sort it out faster.