I installed it using aptitude and apt-get but still after purging reinstalling everytime i try to use rfkill in the terminal it will say command not found.
You have got to run it as root.
It does not run, nor it is found as a regular user. It resides in /usr/sbin, that is only searched and used by root. Normally the /usr/sbin/ and /sbin directory house binaries that need to be run with special privileges.
If you defined a sudo user, you can run it as