You can enroll your MCI bill to be paid by any credit card by signing up for the "Online Account Manager" at this site.
https://www.mci.com/cgi-bin/WebObjects/oam.woa
I was told by them that you get 7 miles per dollar spent,if paid by credit card, but the site only mentions 5 miles per. We will see.
But you WILL get Double Miles per dollar spent thru all of 1999, if you use the Delta SkyMiles Credit Card, because MCI is a Delta partner (same with Red Lobster,Olive Garden, Hertz, and 1-800-FLOWERS).
Also, while at MCI's site there is a calling plan that is offered only on the Internet. It is called MCI ONE NET SAVINGS.
You can switch to it with the click of a mouse. It requires credit card billing. All your statements are online. They notify by e-mail when your invoice is available to view online and no paper statement will be mailed to you.
Best of all, the rates are better than anything offered to me over the phone when I signed up for the 25,000 mile offer. I was assured that it will not impact any mileage plan I am currently in by switching. I hope not cause, I like those 15,000 mile deposits every month to my SkyMiles account. (I have three lines signed up.)