In what way are your files appearing as mpeg?

If the files have an mpeg extension (.MPG or .MPEG) then you are downloading the wrong files.

If the problem is that MP3 files have been associated with the wrong program (a video player perhaps) then the solution depends on your operating system and the normal audio player that you use.

If you are using windows - then MP3s may be associated with Windows Media Player - this isn't wrong - they'll get played. If you want to associate them with something else - then there are several ways to do it - but if you're not running windows I can't advise...

Mark