Ask HN: How to leave Linkedin?

Once I joined Linkedin, but I find their service and many e-mail messages disrespectful, deceptive, distracting, insulting, and infuriating. At their Web site I tried to cancel my membership or at least stop their e-mail messages, but I saw no way to cancel; I couldn't log on using any of the three old passwords I have for them; and to stop the e-mail messages giving them only my e-mail address I went through several of their captchas with no success and gave up. At their Web site I could see no other way to contact them. So, at the SEC site Edgar I looked up their mailing address and phone number and called them. All I could get was just a recording that gave their FAX number. I wrote them a letter and tried to send via FAX, but their FAX line seems permanently busy. So, I printed a letter and will send it USPS. Somehow I suspect that the letter will be ignored. Is it nearly impossible to get Linkedin to cease and desist? Is there a way?