Problem with Alcatel One Touch Idos 2s smartphone. Problem with the software (description of the problem inside the question). What to do?

Question

Android

The problem has been present since purchase. In short, it hangs, slows down.
At first, the desktop just loaded for a long time after exiting applications, then the keyboard did not open in the browser and other applications for a long time.
Applications such as Google Chrome often crash.
Over time, a little later, there was a problem with the native player, which began to slow down, and the audio jack - when playing in headphones, the sound began to disappear, although the music continued to play in the player.
The screen response has decreased, it does not respond well to touch.
The software has not been updated, it costs native Android 4.3 Jelly Bean
What could be the problem, and whether it can be solved, or does it still need to be taken to the service. The warranty hasn't expired yet.
Thanks