Thank you all!
They finally changed my phone! At first they told me that this is a minor issue and they don't know if they could change the device for this......
Hahahaha in their dreams...........! I went to they store manager and I make him take my device and compare it with the store's demo device.. Finally he gave me a new one..
And it's working perfectly!!!! I really love it! I was very dissapointed at first with the other device because I was thinking that maybe that's how the phone is or I should be waiting for an update to fix their issue...
Thank you all for your responses! You were very helpful! I'm very happy to belong in your forum community and from now on I will be very happy to help where ever I know my help!