On Ardex, go to Settings > Options and Settings
Go to Licensee
Change the address as required
Click Save

Go to User Info
Change the address as required
Click Save

Once you have done the above, please make sure to check for updates for reports. To do this, simply:
On Ardex, go to Help > Get Report Updates

Click Check For Updates

And then you can try to view your statements to see if the new address now appears on the statements.