Broken Game Systems

I have encountered several severe faults with the system in the online play.
1) The currency registering factor was incapable of registering the fact i had well over the amount i needed to purchase an item, but would not let me purchase. 2) I was removed from a match for getting a head shot nearly two seconds after i re-spawned, the system removed me for said "hack", many other players are able to do this action with recourse. 3) The melee range for the mutants in Mutant Mode is very glitched, some people are able to hit at point blank, others can hit from several meters away. 4) The hack remove system has not removed people that actually hack on many occasions, I have been in Search And Destroy matches where the team was killed before the round would let us move and/or shoot.