Spamalot
I signed up for this but didn't use them ultimately as I found much cheaper deals for what I was looking for elsewhere. Since signing up I've been constantly spammed with emails. The unsubscribe link in the messages takes you to a webpage that appears to have Russian text on it. Translating the page in to English says "you have not unsubscribed from anything". Nothing else, no link to another page, so a pointless exercise. Logging on to the site and attempting to close my account was a waste of time too. No options to close the account or specify mailing preferences. It all seems very amateur for an online company that has supposedly been running for seven years. Last ditch is to email them directly, but I don't hold out much hope I'll get a response. Clearly they don't want you to unsubscribe or they'd make it easy, like most online services. Update: After emailing I received a response to advise my account would be closed and the constant emails have stopped.