Random selecting 20 items base on criteria with no duplicates

Ok here is the scenario,first take a look at my workbook please. Then refer on Column A to C about the criteria, The thing is on Column F to H will be my data and on Column K to L will I have to put my result, I have to select 20 item only out of 24 entity code randomly without duplicates on Country and Entity code, Account will be ok if it has duplicate. On the sample table, for example on PH country there will be 4 entity code and I have to select only 3 entity code out of 4. I tried the random function and I am having a difficult times because it still selecting duplicate record. I hope someone could help me