A strange glitch happened to me today. I started a match being level 8. After the match I was levelled up to 19. Almost all my weapon stats got cleared except for bow (I used it only few times before, but after this level up my stats show 180 kills with bow). Kill counts for SCAR, Feline, Jackal and Typhoon which are used on the first 8 levels are cleared.
Not that I don't like such quick promotion, but it is still a bug.