Turn on roaming. Reboot your phone. Manually select either AT&T or T-Mobile (voice services will only work with T-Mobile).
According to T-Mobile's website in areas where there is no 3G network but has 2G network coverage your phone will automatically drop to 2G when recieving or sending a call. However you will not be able to use your mobile data or text during the voice call. You may find this post helpful....
With the new self service account, it should a simple one step process. Once you purchase the add on, it is automatically activated. Did you get a welcome USA text from PM? Do you seen either signal from T mobile or AT&T mobile?
