Marketing email's subject made me think my card got hacked
A hostel company I stayed with a while back emailed me with the subject: "Your booking is confirmed!". This made me frantically check all my accounts since I hadn't booked any hostels recently. I was super concerned until I opened the email and saw... it was a stupid marketing email...
This kind of marketing should be illegal. Don't use Clink Hostels.
Send a message to their help desk saying you got an email confirmation and would like to cancel it. Act very confused about the situation. Waste their time and make it their problem.