Why did you lock my thread?

I asked why Cox sends letters with "IMPORTANT CUSTOMER INFORMATION INSIDE" on the envelope.  A Cox representative posted a link to changing Promotional Settings.

Okay.  I did that.  However, the abuse of that phrase by the marketing department was NOT addressed.  Even though I have now indicated that I do not want ANY contact for promotional purposes, I STILL will never open a letter from Cox that says that it is important, 

BECAUSE YOU HAVE TRAINED ME THAT IT IS JUNK MAIL.

Thanks for the information on how to block this junk in the future.  No thanks for failing to correct major marketing abuse.