Verify that the order confirmation email (containing the voucher) has not been sent to SPAM and nor it has been blocked by your email provider.
Make sure that you did not enter an incorrect email address when purchasing.
If the problem persists
Verify that the order confirmation email (containing the voucher) has not been sent to SPAM and nor it has been blocked by your email provider.
Make sure that you did not enter an incorrect email address when purchasing.
If the problem persists