No sim card detected

[Android Question]

Samsung Galaxy S III GT-I9300 - 16GB - White (Unlocked) Smartphone, i tried with 3 different micro sim cards from different phone company's is not reading the sim card. is there any thing that i can do to make it work?

 

[Hadron]

I'd contact the vendor, I'm afraid. If it's not detecting the SIMs at all that suggests a fault to me (at the least it's not actually unlocked, so not what you paid for, but "not detected" sounds more serious).