Are you sure you gave the correct email address, some instances of a typo in the email address results non receipt ?
Have you checked your spam folder that too can be a reason for non receipt ?
Resend avast License
https://www.avast.com/resend-license-paid.php, you will need to enter the email that you used when purchasing the license, e.g. the one that the original email with the link was sent.
Also try logging in to your my.avast.com account and see if the licenses section has information on your license.
