After owning your Keon for a while, lots of data can build up in unused caches, pictures or other documents, which can overload your devices processing capabilities causing it to freeze. Try clearing out old apps including their caches and moving files to a computer or another storage device. If that doesn't help with the freezing you may need to reset the phone or worst case scenario, re-flash the phone.
If your Keon is having trouble holding a charge your phone may be over working itself if you have too many apps running or too much data on the phone. Some things you can do to improve battery life are to remove unused apps and delete unused data. Adjusting setting such as brightness and mobile data can also help improve battery life. If none of those things help, your battery may worn out and need to be replaced.
If your Keon is having difficulty charging, first make sure that the Micro-USB adapter is properly fitted to the device and plugged into a working wall outlet. If your device still is not charging you may need to replace the battery, Lithium-Ion Batters only have a limited number of charge/discharge cycles they can go through before they become unusable.