I've been struggling with this one for a while... I have the following data table on a sheet called PickupData

I then have a sheet where i'm trying to sum income (col d) where org_code (col a) = the value in row 18 and month (col c) = the value in column a

I've tried with SUMPRODUCT, SUM(IF(blah,IF(blah,x,0),0) (pressing ctrl-shift-enter) and even the conditional sum wizard. I don't think i can use DSUM as it requires a cell range to be passed for the criteria parameter.
I also tried un-merging the cells as i thought this could be effecting the results.
Can anyone provide a working solution?
Heres the test workbook: here
Thanks
Lee