Pivot Table subtotal error

[Tidr0001]

		Actual <tbody> </tbody>	Current <tbody> </tbody>	Needed <tbody> </tbody>
Store A <tbody> </tbody>	Prod A <tbody> </tbody>	3	3	3
	Prod B <tbody> </tbody>	-5
	Prod C <tbody> </tbody>	7	7	7
Store A Total <tbody> </tbody>		5	5	10

<tbody>
</tbody>

I have a pivot table with Store, Products, and Sale or Cost.

Each Store has products that fall under it and some products have positive sales while others have negative costs.

In the Pivot Table, I have a calculated Field where if the product had positive sales, capture the amount.
If the product had negative sales (or cost) return 0 (zero - positive sales)

=IF(Jan Sales > 0, Jan Sales,0)

At the product level, this works fine.

However, when the Pivot Table calculated the Subtotal for each store, it is reducing Sales by those negative sales (or cost) I am looking to remove.