Byen.site is not a prison ! you are FREE ! the termination of the contract, the hosting, ans the SEO on the earch engines is without time commitment. The client is the owner of the domain name, in accordance with the ethical guidelines of the profession.
If you are willing to terminate the contract, you just have to scan a letter signed by you, stating your customer number, and domain name of the website yu're willing to close. The document should be sent by email to email@example.com. You will received your confirmation of your request by email. If you don't recive a confirmation, we might not had received your email, so just contact us at +33 (0) 1 42 46 64 75.
On your letter you should also indicate the wished closing date for the wbesite.The date should be at least the last day of the month that follows your request. For exemple: For an email sent the 20 of decelber, the website will be closed (the soonest) in the 31 of january, so january will be the last month you will pay for.