Cant receive or send pictures or use apps without wifi HELP ASAP!!?

[Raven]

My phone has unlimited texting and calling and im supposed to be able to use my internet and instagram and twitter without wifi, and send pics and receive, but for some reason i cant seem to get pic messages, itll just say downloading, thats it, and when i try sending them it says "unable to send, try later." i have to use wifi for everything but texting and calling, what happened? i have tmobile samsung, thats all i know about my phone, lol. Yeah, what am i supposed to do?

[AVDADDY]

Contact your carrier.

[537]

I have AT&T on my Galaxy Note 2 and I have experience similar problems.

However, on my phone I have my settings to do everything over WiFi only... The thing is... when I am away, my phone immediately tries to search for a wifi signal first... so if I try to log into Yahoo Messenger or Skype when I'm away, it almost never connects because it's looking for Wifi first... I downloaded a WiFi toggle widget that allows me to turn off my wifi.. you can do that from your settings too.. then if you do that... your phone won't waste time searching for a signal first... that's probably your problem...