Follow the steps in the support document linked below to request refunds for purchases.
click here-> Request a refund for apps or content that you bought from Apple - Apple Support
Do note, purchases do not happen automatically. Also, if you downloaded Apps with free trials, those normally turn into paid subscriptions you are responsible for unless you cancel them before they renew. Verify you have no active subscriptions you may not want by following the steps in the support document linked below.
click here-> If you want to cancel a subscription from Apple - Apple Support