Unlocked LG kg800 phone

Hey umm I have an LG kg800 unlocked phone for t-mobile, I got the settings for mms to work, my dad called T-Mobile customer service and they sent me a a text and I used it to get the settings.\r\n

I can send pictures and recieve forwards,
What I CAN NOT do however, and this REALLY concerns me,

I can't get pictures! Like my connection bar, (as any other users of this phone will notice) it has a "g" on the left side of the connection bar, and on the right side of the screen a blue arrow pointing down to say something is recieving.

But then it'll just go back to normal, the blue arrow will disappear, and it'll be like I was never even sent anything, not even a notification to say "download error" or "failed" or anything!

Someone please help! I can get pictures from my email, but not from friends phones??

Same as me HELP PLEASE!!!

change provider t-mobile suxs