Software updates problem

[MohabAOMG]

Hey everyone! I own a Samsung Galaxy S4 (i9500) running on lollipop 5.0.1 & it has alot of bugs
My friends who have i9505 got a software update & all the bugs were fixed but why ain't I recieving an update on my device?

 

[jasonandrews25788]

what's your system version ? and what kind of bugs do you face?

 

[MohabAOMG]

How can I see my system version?
I face bugs like very slow multi tasking, & when I close all apps in the multi-tasking they don't close fully I don't know to explain & the rest are not important!