Call MCI and tell them they are to put you on their DO NOT CALL list -- this is a federally madated list that company's must maintain and cannot call. The company can be fined if they call you.

At one point in time, I was called on almost a daily basis by MBNA -- the leader in credit card co-branding (i.e. the NY Yankees Master Card etc...). I finally called customer service, complained and told them to put me on their DO NOT CALL list and that I did not want ANY marketing material from them. I told them if I did, I would complain to the FTC and make sure they were fined -- I have not heard from them in 3 years!

--Jim