Thank you for your question!
Sorry for replying late.

Do you mean you have made the purchase of a year's Pro account automatically? If yes, did it happen in Google Play? It seems Google play is by default set to "subscribe automatically each year". If you don't want the subscription, you may cancel it in Play Store by:
1. Tap “Account” in sidebar.
2. Tap “Subscriptions” then find Doit.im to cancel.

If any further questions, please feel free to reply here or mail to kassy@doitim.com.
Nice day!