we are flying our drone on a 10-20m*40-50m field surrounded by buildings, we've flown on this field for a couple times in beginner mode before. the tragedy happened this afternoon while we decided to get some footages, it is not in beginner mode anymore. for 4 minutes we flown the drone, it went quite well. we started to realise when we try to oush the left joystick to make the drone fly higher, it raise higher but in the same time the drone accelerates to the right (which is left us horrified as we did not push the right joystick at all). we flew it lower then tried to raise the drone again, this time it flew very fast to the right, going for the building. we tried to pull the drone back but we failed, the drone crashed into the wall but kept on running, then it stop and drop on to the ground from approx. level 2 . we ran to check the drone and found out that the damage was quite severe, the propeller was scratched, rubber of the gimbal broke, back light cover lost, and not to mention the bumps and scratches on the body. then when we try to connect the drone to our phone but it failed.
we got the drone for approx. 6 month not more than a year. we would like to know how can we claim our warranty etc. thanks a lot

It may not be a warranty issue, it could possibly be user error.  Maybe it needed controller or compass or IMU calibration and so on.
Upload the logs off the device to phantomhelp.com so people here can see what actually happened and whether its an operator problem or actual hardware.

Sorry about the crash there, firstly you would need to start a ticket with Dji support and they will give you instructions from there, if you want the guys on here to help tell you what might have caused the issues I would suggest upload your flight log here and post the link back:
http://www.phantomhelp.com/LogViewer/Upload/

The only one's who can determine whether there is warranty coverage is DJI, so I suggest opening an online Chat session (*through the support section of the DJI website) and describe your situation to them.  They will have a few questions and ask you for your flight logs and start a case.  In post #3 Captn Suren provides you with a way to post your flight log here for forum viewing.

Hi, I am sorry to hear what happened to your DJI Mavic Pro. Since this issue happens the best thing you need to do is to get in touch with DJI Support. Please email them at support@dji.com to create a ticket for your Drone. Please sync the flight records of the Drone as well using your DJI Go 4 application. Thank you.

thankssssss so much guys!! so i've contact the dji customer service and they are very helpful and friendly, i've sent an email to them. Really appreciate help from you guys!!!

Hi x y hopefully you get your drone back so you can fly again.

x y Posted at 2018-7-19 02:00
thankssssss so much guys!! so i've contact the dji customer service and they are very helpful and friendly, i've sent an email to them. Really appreciate help from you guys!!!

Hi, thanks for the feedback, rest assured that our team will do an entire evaluation to your drone and provide appropriate resolution.