I am really sorry to hear about your bad experience with the dealer authorized service center/and-or the music store where you have made the PA800 and previous purchases.

Is ashamed that good customer service is hard to find this days.

In other topic, I had no one, but 3 different new PA 800s, and none gave me that problem, check that you have the latest OS loaded, I also have a PA 500(touch screen also, no problem so far).

I hope soon you get resolved all those issues favorably, one advise to you would be to make sure you calibrate your touch screen as soon you get it, and of course, make a backup

of the current resources and save all your performances and user styles, in case that you may have a corrupted OS, I would consider reload the the OS and Factory resources just in case,

with the backup previously made, you can reload your user styles, performances, global, etc...I hope this helps.