Here I am going to share a simple trick for block your enemy sim card,Blocking a sim card is too simple.
What you have to do is just enter the below code in the desired phone:
Entering of above code will ask you to enter the PUK code.To solve this issue just call customer care and get your PUK code.
Note:Entering of invalid PUK will cause permanent blocking of your SIM!
Dont Try if u dont know what u r doing