How to change song order on an Iitronics mp3?

It's a pretty old, basic model. I can get songs onto it fine my putting it in the computer and transferring the files over, but the songs in the folders on the mp3 are in a different order to on the computer; irritating when trying to make a playlist.

Anyone know how to change the order of the songs in the folders on the mp3 player? Thanks a lot for any help.