error in my doogee X10 system

Recently my phone switches off and talks a very long time to start sometimes it takes the entire day. It only works when I remove the battery and put it back but when it works it's slow and often restarts without even 5 minutes of use. I have reset my phone 6 times. Yesterday an error was found on my phone's system. How do i fix this? My phone was recently bought a month ago and I don't have the slip