I Phone5s slow

[nipunali]

I am Bangladeshi. I have a I phone 5s . This phone is very slow working day by day. When i want to update my I phone 5s. Suddenly Switch off. What i do now?

 

[Just_Me_D]

Make a genius bar appointment with the nearest Apple Store. If there isn't one near you, back up your device and then restore it via iTunes.