i need 120 million credit wg how?

TeriyakiTanker: Well if you refuse to do it that is on you....... The game design isn't going to change to make the economy any easier, so you have two options if you don't want to spend money.  Doesn't matter if you it or not, it is just the way it is.   You need to grind your Tier VIII and VII premiums until you have the 120 million you want.  The more damage and assistance you get the more money you will make.  Right now you don't do that very well so you don't make a lot of credits.  Improve that and you will improve your credit earning potential.  Perhaps join a clan and platoon with some players and that might help.