Corporations are people too. It doesn't seem to me that corporations are central to the problem here. We should also note that corporations and free market economies are why we have such high standards of living in the developed countries. And high standards of living help make it possible for us to be civilized and decent and have resonable levels of security and lower rates of crime.
Generally speaking, I think Congo could use more corporate involvement. The real problem IMO is these armed gangs of criminals, not corporations. Because if there was safety and security, corporations could help raise living standards.
The problem here is that there is already corporate involvement in the DRC, and that to exploit the mineral resources that draw them to the region, they deal with the armed groups involved withthe conflicts, (they have no choice, really). Without oversight from either a strong and noncorrupt state government or some sort of international regime to monitor and control activities and make sure operations aren't supporting actors in the conflict, their actions are not, and won't lead to an increase in living standards or heightened civility in the region.
How to fix this issue is a problem beyond me, though, I sadly don't see it getting better anytime soon.