Why can't I text or call with my iPhone 4?

So my aunt came up to me and told me she tried texting me but i didn't answer. I assumed I could text cause I been texting my friend before. I tried sending a text to her but she didn't get it. My friend also has a iPhone 4S so I think that why we could text. I have virgin mobile and we tried calling the service but they didn't really help and kept asking the same info and didn't seem to understand. In short It seems I can only text people with iPhones(and with iMessage on) and nobody else. Also when I call someone it tells me my call be will recorded and I got no money on the phone but I can text my friend? Someone please help

IMessage will always work from iphone to iphone as long as you are connected to wifi. If you dont have any money on the phone then that means you cant make calls and text messages to and from any devices. Other than iMessage, which will always work to and from iphones as long as you are connected to a wifi spot.