I have recently bought one plus 6 mobile from amazon app.after getting the mobile after switching on the mobile I was asked for system updates then after the updates are done a blue spot light has appreared at the bottom of the mobile.initially I thought that was due to android updates so I called the customer care of amazon and informed them with the same problem I am facing.the next day amazon have sent their technical support guy to check the problem of the mobile but unfortunately the support guy also was unable to know the problem hence he suggested for a replacement of the mobile, but when I have contacted the amazon guys they said that they cant do the replacement as the seller don't have the mobile in stock I got very much irritated by this kind of reply from amazon people.then with the help of one of my colleagues I got to know that there is a one plus service center and I went there and explained them the problem and I got my problem rectified as they have replaced my front screen display with out any cost.now my mobile is working as I wanted it to work.thanks to the service center people of one plus.