You cancel from your dashboard at me.melodreams.com, and only there. Open the Account section, go to Subscription and Billing, and click Manage Subscription. The cancel option is inside.
What happens after
Your subscription stays active until the end of the period you already paid for. You do not get charged again. Nothing is shut off immediately.
After the period ends
Your page stays online. Your account goes back to the free plan and keeps working. Anything beyond the free limits stops showing until you resubscribe, but nothing is deleted, and you can pick up exactly where you left off. This is part of The Promise: we never take your page down to make you pay.
To fully delete
See Delete your account. Cancelling and deleting are different actions.