If the report does not show, it is because of the following reasons:
1) you did not add the test id string to the message; or
2) your email system or server did not send the message to the seed list; or
3) the receiving servers blocked the messages and they bounce back.
You can delete the test that didn’t deliver a report and the credit will be returned to your account.
Then you can create a new test making sure that you copy-paste the right id string to the message and that your email system actually sends the message to the seed list.