Impossible to Unsubscribe from mailing lists!

It is impossible to unsubscribe from Netflorist's newsletters. I have manually unsubscribed from every newsletter they have sent me in the last two months. I have gone onto my Netflorist profile and ensured that I am not subscribed to any newsletters there. The Opt-Out page on their website has been broken for months. I have emailed Netflorist directly and asked them to unsubscribe me from all their mailing lists. I would block their domain name on my emails, except then I wouldn't be able to receive order confirmations when I make purchases. Please, for heaven's sake, stop sending me spam, Netflorist!