In first part you should solve the No-Data part since there is no data for the combo abc-rent.
In order to it you can use the lookup function, and force a fake lookup using 0 as parameter.
LOOKUP(SUM([Something]),0)
Then you can use ZN function and force a zero for a null value, which is different from No Data.
That being said, you should be able to get something like this:
Create this calculated field:
zn(LOOKUP(max({ FIXED [day],[employee],[reason] : COUNT([reason])}),0))
EDIT
If you want to have grand totals, i think this should be the better solution:
And the Calculated Field is a pure Count nested in a lookup function as said before:
zn(LOOKUP(COUNT([expense]),0))