Nokia Lumia 1020 Straight Talk mms settings

[lunaMay]

I know this subject has been covered before but hoping some one out there can give me some info I haven't tried. I bought the 1020 a few days ago and put my at&t straight talk sim in. I have data and text but no mms. I have tried every setting I could find out there and nothing seems to work. I took my phone into some "phone guys" and they couldn't even figure it out! Any advise?