My local files from Spotify PC version don´t sync in my iPhone

[FeeLD7H]

Dear users, 

I have a problem with my iphone.

I have some playlists with local files. I synced my iphone with Spotify and it appears in devices. The problem appears when my playlists are synced in my phone without the local files. I don´t know what I can do to sync my local files. I followed the instructions from Spotify to sync my phone with PC and tried some tips found on the web but it didn´t work.

Anyone know how can I fix this small problem?

Thanks!

PS: I don´t know if anyone had this problem before or something. Also I don´t know if this message can stay here or it goes in other place. Sorry about that.