Transferred credits went missing


My department purchased a total of 600 credits (once 100 credits, the other time 500 credits with additional 50 credits courtesy) and transferred them to my account. So my account should have a total of 650 credits. However, I only see 260 in my account. Can anyone let me know how to check the status of the credits? And who I should contact regarding the credits?

Thank you so much!