Please Help

i bought a premium anti virus, but i entered wrong email address.how can i get the activation code?

Have you read this: https://support.avast.com/en-us/article/Locate-Activation-Code

You can also try this: https://support.avast.com/en-us/contact/sales
if an order ID is required type 0000000 (7 zero’s) and explain your problem.