I had a little go phone and it broke (screen snapped off). I replaced it with another phone (not AT&T), which has a new number, but I'm wondering if there's anything I should do to deactivate the old phone, and is there a way to forward or obtain any calls I may have missed? I think I may have missed some important calls. I kind of threw the old phone away without turning it "off," so it might actually still be receiving stuff.... I don't know, what ought I do?
I would just let the old phone expire by itself. Let a sleeping dog lie.
Unfortunately, there is no way to retrieve any missed calls/text messages, etc. without actually having the phone working. I would just try to direct your contacts to your new number so that you can be reached from your new phone.