MP3 downloads to cell phone not working

Question

saved a lot of music from my pc to my memory card and am SUPPOSED to be able to get the music to my phone. Apparently MetroPCS knows NOTHING about getting this onto my phone, Sooooo...what's the point of buying a 200.00 cell phone with that feature, but the memory card isn't recognized by the phone?! i don't know if i should just leave the memory card out and just use the USB port to bypass the memory card upload music that way