Multiple Criteria - I give up and need help

All I have been trying to do is create a formula on tab combined file cell I2 that lookup two criteria
1st criteria
Combined file tab cell A2 to tab ORACLE matches column A
2nd criteria
Combined file tab cell B2 to tab ORACLE matches column B
Return Criteria
Matching ORACLE Tab column C

I am frustrated please help.

Combined File.xlsx

You have two choices:
1) Create a helper column on the ORACLE tab that has A&B combined (i.e. - in D2 add the formula =A2&B2 then copy down)
Then you can use the formula (Combined file cell I2): =INDEX(ORACLE!C:C,MATCH(A2&B2,ORACLE!D:D,0))
2) Use a CSE formula (Combined file cell I2): {=INDEX(ORACLE!C:C,MATCH(A2&B2,CONCATENATE(ORACLE!A$1:A$305,ORACLE!B$1:B$305),0))}
Enter the formula then press Ctrl+Shift+Enter to get the brackets (array) formula

Option 2 takes more memory, but then you dont need to change your ORACLE tab.

I used the # 2 solution and it worked. I just don't understand enough about excel yet to understand how what i was doing wasn't working or why what you did worked either. I might try to explain what i was trying to do later but for now thank you very much.