my imei block now no sim card work my iphone

Go to Settings > General > About > Carrier Lock. If it says it is locked look and see what network it is just below there.

If your phone is locked to a specific network provider then only that netwpork provider can unlock it.

If you did not get your phone through them, they are not obliged to unlock it (depends on country)

Apple cannot help.

If, as you said originally, the IMEI is blocked then maybe the phone is on a stolen list. Again talk to whichever network provider locked it. It isn't easy to find out which provided did lock it if the phone is pre-owned.