If you believe you have lost your medals, keep in mind that we store your account balances and progress on our servers, not on your computer. This means that an interruption in your connection--even for just a moment--can cause your game to load incompletely, which can make it appear as if you've lost your medals. This same phenomenon can cause technology and units you have already unlocked to appear locked, and it can make it appear as if you are missing event progress, Blood Thorium, and other items.
Luckily, 99% of the time, all you need to do to correct this problem is clear your cache and refresh your browser. This will cause your computer to re-sync with our server and load your missing content. Please try this before contacting KIXEYE customer support about this issue, as this is almost always the only fix required.