Hi @Ve7say, welcome to the community, and thanks for your post! When your subscription has expired, you'll no longer have access to the actual download feature, but it's possible some of your tracks would remain cached for a time.
If you're looking to restore storage space, you can delete the cache from the settings of the Spotify app on Android. It's also possible you'd need to go to apps in the settings section of your Android device and clear the app's storage from there. You might even prefer to perform a clean install of the app; instructions for that can be found here.
Hope that answers your questions, but let us know if you need any further help!
Help others find this answer and click "Accept as Solution".
If you appreciate my answer, maybe give me a Like.