IPhone 5 Simple Mobile activation problem

I recently just bought an iPhone 5, and I unlocked the phone using unlockthatphone.com and they said that my iPhone 5 was officially unlocked forever.
Now here is where my problem comes in.
I use Simple Mobile, and when i put my sim card in the iPhone 5 and plug it into Itunes it shows my number and when i look at the iPhone it says No Service.
My question is what is the problem with this?
i got a new nano sim card put it in and everything
what is the problem?
ps i know simple mobile is compatible with iphone 5 and has nano sim cards.

That means your iPhone 5 is not unlocked, it's still locked. When you unlock your phone, it becomes compatible with any GSM carrier and you should get signal on SimpleMobile. You can contact this person (arghyle@rocketmail.com) who can help you get the phone factory unlocked permanently.