I recently bought an Acer Iconia A500 off ebay. The tablet I bought was not advertised as a demo version, but when I went to set it up I couldn't assign a google account or download any apps. When I looked at the build number I found it was a demo. If I can't get the seller to refund my money is there a way to replace the demo software with the stock retail os, or can I download apps on it some other way?