All MP3 files are opening in Spotify app.

[PAB123]

I have downloaded and purchased some MP3 files and no matter what I try, they are defaulting to Spotify to open them. I don't have a paid Spotify account so I keep getting an error message when attempting to listen to them.  I tried going into settings for the Spotify app but there is no place to change the setting. Help please!!! 

[PAB123]

As soon as I click Open With, Spotify opens and I get the same error.

[PAB123]

A health company. They have no idea either and have just credited me for the purchase. 

[PAB123]

I like Spotify and use it daily.  Not planning to uninstall it just to make these files work.  Thanks anyway.