ATT UVERSE Internet speed slow?

so I'm paying ATT Uverse for 6mb/s speed but when I download from the internet, I only get 350kb/s, and this is for evwry computer for the past 3 years. ATT wont give me a valid explanation. Please help!|||It could be that the places you are downloading from are only capable of that speed, or ATT isn't giving you your full speed. Have you tried speedtest.net to check?