I called them and was told that the iPhone 5 is not supposed to work overseas. I said that I was told I can use it outside US because it's international unlocked, then the representative told me that I need to go to a local carrier for unlocking the device. I was confused with that how can another carrier unlock a device from Cricket... And I asked this question, this time the CSR told me that I need to go to a Cricket store close to me, to see whether they can flash the device to unlock it. Ha... I took this answer as a shifting off manner... Called the local store, they said they don't know how to cope with this. Apparently, the Cricket hasn't trained their representatives yet!
I also called the sells again, pretending to be a new customer for asking whether I can use it internationally, and this time I was told I cannot use it unless they have signed an international roaming agreement with local carrier there, and it means the only country I can roam to is Canada, maybe Mexico!
BTW, where did you activated the device? I know you activated it in the US, I meant was the city the one Cricket is selling iPhone? So that I can figure out whether this phone would roam on other networks inside US, as the representatives also told me that the usage is not guaranteed inside US when it's not working on their own networks.
Update: Wired! I called the sells team again and asked the representative for transferring me to customer service, she asked me what did I want and I told her the problem you encountered, this time this representative told me that this phone is supposed to work outside the US as it's international unlocked...