Use the search bar to search the Community for your issue. Odds are someone has already reported it. If so, reply in that thread and provide as much information as possible.
If no one has reported an issue like the one you're experiencing, navigate to the relevant forum for your device in our Help boards section and post a new thread there.
Again, make sure you provide as much information as possible.
Didn't help? Search for more Spotify Answers, or create a new thread and ask the Community.