How to activate FaceTime & iMessage?

A few months ago I tried to activate FaceTime and IMessage without any positive result.
Active button activation, I asked my Apple ID, I login and reads "Waiting for activation ...." after a few minutes he says, "Activation error. Active FaceTime to try again", "Activation Active IMessage wrong to try again. "
I've done everything like changing my time zone for the Sau Paulo Brazil, Ecuador Quito, until I made ​​an additional recharge my phone plan because I read that the activation is sent IMessage FaceTime and international SMS activation, but despite of all possible solutions will not achieve or IMessage activate FaceTime. I believed in the possibility that in Peru there is no such service involved in the iPhone, but I find that Movistar and Claro users if they are active.
It should be noted that my iPhone 4S is the operator AT & T U.S., but I use it unlocked in Peru.