you really need to give us a little more to go on here.
I presume that you mean that you can't receive calls or call anyone?Otherwise I don't see your problem.
When you say your SIM card is not working - you are sure that your phone is working correctly? what phone is it?
Is this a recent problem? Was it working fine previously? Do you have credit or available airtime?
What does your phone display to lead you to believe that your SIM card is not working?
Does it display something like: "SIM card registration failed" ?
If you can provide more information on your problem, someone may be able to help.
If you want to say thanks > click 'Kudos'.Answered your question? > click 'Mark as Helpful Answer' also.