It seems a lot of folk running android 4.4.2+ have had trouble getting spotify to use an external SD card for its cache. I just bought a card for my android so I thought I'd give it a try and it worked!
Steps I took
I still see a com.spotify.music folder in internal storage but it's empty now.
If you have previously been using spotify with an external SD card, I recommend that, in addition to the steps above, you reformat the card in the phone before reinstalling spotify music.
Solved! Go to Solution.