I didn't get the premium, even though I paid for it

I paid for premium yesterday through the App Store but I can’t upgrade to Premium and I didn’t receive any email confirming the purchase.

Sorry to hear that. Are you sure that you were actually charged? Did you received payment confirmation from Apple?
If yes, please go to “Upgrade Screen” → “Free 7 Day Trial” → “Restore Previous Purchase". That will grab the receipt from apple and then re-send it to the server.

Yes I paid. My card has been charged.
I sent you an email with detailed information.
Thank you for the quick response