heyhey! I'm not completely sure about how that happened, but if you don't get the response you're looking for within this thread, you can always get help with bugs here if you have any issues. Hope I could help, good luck!
When you gain credits, such as when you're getting kills/winning games does the number go up or is it stuck like that? I'd recommend posting your account info (In-game name) and a screenshot of your credits in a Bug Reports thread here: https://mccentral.org/community/forums/bugs/ if there is an issue with your player profile someone from the Quality Assurance/Administration team will fix it.
