I was not logged in when i made a purchase on the avast site for avast premium. Now, I have not received the confirmation message and the subscription does not show on the account email I mentioned while making the purchase… Dont know what to do!!!
Can anyone help! 
How did you pay and when ?
Was the email you used the same as the one used to logon to the forum ?
If you click on the avast tray icon and select Registration, does it show anything ?
If not click on the Go To Account, is there any information there ?
The most common cause of non receipt of the confirmation is a typo on the email address or it being sent to the spam folder by your email client or email provider.
So you have installed Avast Premium, it should still run for a while without the registration.
I paid with my debit card yesterday i.e. 18/9/2021. Yes, I used the same email to login. The account settings do not show anything in avast neither the subscription page nor the payments page. I have the receipt of the transaction also a mail from the bank stating payment made to avast.
With a Debit (Bank) Card, I’m not sure if the Registration and email would be sent immediately, but when the transaction and funds are transferred.
It could be that since this transaction was only yesterday, a weekend. I would give it a few days to see if it resolves itself.
If not you can contact avast using a support ticket, but that would require some information, email (from avast) and order ID number so that they can find your order.