Sometimes your browser will store a copy of the Packs page and a pack credit that you earned either in Packs or Sets will not show up.
Try to force a full refresh of the packs page by navigating to the Packs page and then hitting the following keys (depending on your Operating System):
- Windows: Ctrl + F5
- Mac/Apple: Apple + R or Command + R
- Linux: F5
This will force your browser to retrieve a fresh copy of the Pack list from the MUT Watch servers - and will include any new credits you may have earned