hisense U962 problem

I bought 2 x Hisense U962. This was the worst mistake of my life. the battery doesn't hold long and the phone freezes sometimes. Some of the aps I am running on the device just exit's without any reason. Now the phone shows me to do a wireless update. It downloads the update and then starts to install it it just says error installing update. Then you need to remove the battery to reset the phone.