Wrong purchase

Hi there

I purchased Theme Zone app for 0.99 usd and i saw that there was an extra 49.99 usd deducted from my account for a Jigsaw Master game which has been on my phone and i haven't used. I definitely did not authorize for this payment as i was only purchasing the Theme zone app. I unsubscribed from the app but i'm afraid my money might go off again in the future without my authorization. Lastly is there a way i can be refunded the 49.99 usd deducted as it was not my intention to purchase that app?

Looking forward to your prompt feedback