Make sure the APN (Settings/Connections/More networks/Mobile networks/Access Point Names/<your carrier>) has the correct settings.
If you don't have them, that should be a Straight Talk phone, so get on their facebook page (that's where their best techs are) and ask for help. (Put the entire problem in the first post, not just "I need help", including the phone [Centura]. That way, you get the right person, and s/he already knows what the probable causes are.)
There's a Sprint version of that phone. While I think Straight Talk uses the AT&T or TMobile version, if they're using the Sprint version, that's a Sprint problem. They're claiming all sorts of things, but people on Sprint have been having problems with voice, text and/or data for days now, and there's nothing Straight Talk can do about that, so if that's the answer you get, it's legitimate.