how do I turn off the auto sort function in excel
 

I have a pivot table and I have added new data to the data area. When I click
refresh the new data will not added to existing data rols on the pivot but
rather as a new number. For example of I have data showing sales in December
and I input new line items in the data source. I update my data source
parameters and hit refresh. When I do this two decembers are created. One
with the data already present and another with the new data. Why does it not
add all together and create one december?