Ok so finished on all the main missions and the only what i need to unlock items on the challenges. So i seem to be stuck at level 14. i try multilayer whelp the xp seems to get reset after ever mission since i don't seem to get any. I try solo mission same thing. (off topic but still have to play will no sound or the non-stop popping and sound going out just down right hurts my ears)

So what to do now?!