Your .wma files are infected with DRM (Digital Rights Management), this severly restricts what you can do with them.
These Teclast players and nearly all other Rockchip players don't support DRM, thats why you can't play the music that you have paid for, in other words you were ripped off.
You will need to use one of the utilities available on the internet to remove the DRM before the C260 can play the files.
