Free Trial Trap? Spotify Keeps Billing After Cancellation

It has been months since I canceled my Premium subscription, but Spotify still insists on charging me every month without fail. They already employ various tactics in their free version to persuade us to upgrade to Premium. I had to put up with those annoying ads, and even after waiting a whole day to listen to the song I desired, I eventually gave up and uninstalled the app. I'm just sticking with my account for now, but once I deal with this mess, I'll be getting rid of it as well. It's disappointing and amusing for such a large company to resort to taking our small ₺1 like this. It's best to avoid giving any money to that company or going through the trouble of opening an account. I kindly request immediate attention to this matter.