Can you share the sample input and expected output?
How about this expression?
DT_Final = DT_2.AsEnumerable.Where(Function(r) not DT_1.AsEnumerable.Any(Function(r2) r2("Phone").ToString=r("Phone Number").ToString)).CopyToDataTable.DefaultView.ToTable(False,{"Date","Phone Number","Currency"})
You can check out this thread
Regards
Gokul