Three more reasons:

1. Looking at my final MCI bill I noticed that I was once again suicidally overcharged. There were two problems with it. The first was the same overcharging as below. As before they (eventually) fixed that up. The second was in the last five days of my service with them the rates on my calls (to a cell phone in Japan) went up from 14¢/minute to $7.81/minute! The customer support rep (and the customer support specialist who I was transferred to and her manager) were not willing to do anything about this. They gave me the steps to escalate, more later.
2. I just noticed there is a $40 charge from MCI in April that doesn’t appear on any of my statements. The MCI rep I spoke with couldn’t see it either and told me that I had to call the finance department on Monday.
3. They discontinued my service in my first month with them after accruing a whopping $35 in charges!!

On a happier note, I also got my first bill from AT&T. Unfortunately they also lied to me, fortunately I don’t mind. Instead of charging me 12¢/minute to a cell phone in Japan like they said, they charged me 10¢/minute… 10¢/minute!! This is to a cell phone located over five THOUSAND miles away!! This is only a penny more than it costs me to call my parents who live 40 miles away!

I haven’t seen anything, including those 10-10-xxx numbers and any pre-paid calling card that can beat that rate (again it’s to a cell phone, I realize that calling a land line in Japan can be cheap as hell).