Excel Macro does not render Pivot Chart's axis text correctly

My users use excel macro heavily for reporting in Confluence. And they usually use Pivot Chart to show statuses.

In some cases, when the axis texts get too long, they change the axis texts to display vertically, instead of the normal horizontal display.

To reproduce this:

1. Create a page in Confluence.
2. Attach the excel file, Defect.xlsx
3. Use office excel macro to display the excel file.
4. After preview/save, it shows as
   
5. But when you open the excel file in Office 2010, it shows