Merge duplicate cells or Keep duplicates in one column if one of the rows has data

Dear all, am trying all day to find a solution by googling, didn't manage!?

I have a huge document that looks like this

Column A______Column B_____Column C
100/12__________B___________$
100/12______________________@
100/12______________________€
250/13______________________€
250/13______________________$

I want to keep in ColumnA all three rows of 100/12, because it has a value in Column B in one cell-which is the criteria, and remove the 250/13 because it has no value in cell B.

I was assuming that merging duplicates in column A, and than remove empty from ColumnB, it will solve the problem, but i do't know how. Or any way, please help!?