Same phones, but one with much worst camera

[wrigduo]

Hello,
recently I bought two Samsungs GS6, one for me and one for my sister. All are bought in same store and at same time. They are equal in every aspect but only different in camera. Sisters got much worse camera then mine although they have same cams settings.
Anyone know where the problem is and how to fix it? and did anyone had problem like this?
Thanks.

 

[anon(632115)]

It may be a good idea to go back to the store for an exchange. Take both phones so you can demonstrate the problem otherwise its going to cost you money