Photo Grid Unauthorized Billing Through App Store

I clicked on the 3-day free trial option for the Photo Grid app through the App Store. However, without any confirmation or prior notice, an amount of $39 was charged to my credit card ending in 0020. This charge occurred immediately after I started the free trial, even though I downloaded the app only to try it.

Despite attempting to cancel the subscription and trying to reach Apple customer support, I have not been able to achieve any result. I have never experienced an issue like this before, and this situation has caused me inconvenience and financial distress.

I request a full refund of the amount charged and the cancellation of my subscription.