iMessage is unavailable when I try to turn it on?
Basically, my messages on iMessage weren't sending to my mom so I figured I'd just restart my phone, and when that didn't work I decided to turn off iMessage. Thing is, when I turned of iMessage I literally couldn't turn it back on, when I tried to it said "iMessage is unavailable - Turn on cellular data or use Wi-Fi to set up iMessage." Then it automatically flipped right back off. I had my Wi-Fi on, and cellular data, so I knew it wasn't that, so then I reset my general network settings to see if that'd help, but I'm still having the same problem. What can I do?
iPhone 5c, iOS 7.0.4