I Face Difficulty Canceling My Mantal Subscription

I live in Trois-Rivières, Quebec, Canada, and I am a French Canadian user of Mantal. I had a Mantal subscription, but I have mental health difficulties and low mood, and I do not want to continue with this service anymore. I no longer wish to use Mantal, and I would like my subscription to be cancelled as soon as possible so that I am not charged further. I am asking you to end my subscription and confirm the cancellation in writing.