Weapon from grades damage 2500 after exit game

As i opened grade (Anaconda Adv.) i won K2 for 7 days then i exit the game and at the next day it had 2500 damage. The same with other grades p90, awm camo, micro galil, sg552 camo and other 7 days weapon with health 2500 gp was completly broken after exit and reenter the game. To mention no one have my login and my stats didnt changed.