The Call of Duty code that you received from Little Caesars is case sensitive, so you'll want to make sure that you enter the code exactly how it's listed. Here’s a few suggestions that can help to troubleshoot this status:

1. Make sure to only upload one case sensitive code per day

2. You might want to try your link on a different browser or device.

3. You can also try on both a wifi and cellular network.

4. You can clear your cache, cookies, and browsing history for the site.

5. Finally, Once the data has been cleared, then you can try your link again on a private or incognito browsing session.