IF formula with 8 conditions-or better formula

[koklok]

I need one formula that will do all this in column G:
1. IF "VI" in H column return answer in colum G is "MIX"
2. IF "MC" in H column return answer in colum G is "MIX"
3. IF "BL" in H column return answer in colum G is "MIX"
4. IF "DI" in H column return answer in colum G is "Discover"
5. IF "AX" in H column return answer in colum G is "AMEX"
6. If column H is empty look into column I and if "PFEE" answer in column G is"FEE"
7. If column H is empty look into column I and if "IA" answer in column G is"FEE"
8. If column H is empty look into column I and if "CB" answer in column G is"CHBK"


I tried using lookup formula but it's not working for some reason
Any idea how to solve this

Thanks