There is some reason about this case

1. If you pay via Card, but you see the screen of failure and after few minutes, you dont see any email.

It means your payment was held by your bank, please contact them to release your payment.

2. Your account is Free.

We sell Premium key /  coupon code / voucher code. We do not sell Premium account, so you have to apply the code by our instruction to get it works. 

We do not activate your premium for you, you have to do it by yourself! Because we do not know your account password.