MCI dishonest billing (international) ripoff deception Denver Colorado

It's been the third time now that I check my billing in detail (I do this once per year and go over all the previous bills) and I find unbelievable discrepancies between what I am charged and the plan I signed up for. Three years ago I signed up for an MCI international plan for a given fee (say, $3.95/mo) at particular rates (say, 10c weekdays, 30c weekends, calls to Western Europe).
What I see is that, without any warnings, both the fees and the rates have gone up gradually, over the months (the fee has doubled actually)... When I check my account on-line, it says I'm signed up for the Weekend Intl plan, with a monthly fee of $2.00 (I'm now paying $7.90/mo), weekend rates = 9c, weekday rates = 17c (I'm charged 27c/min instead).
How can there be such obvious inconsistencies ? I'll try calling again tomorrow (7/24 friendly customer service is advertized on the web, but sure enough there is no human customer service on Sunday it appears).
As I said, this is the third time I notice that my charges go up over time. Of course, this is not as bad as the wireless nightmares I've been reading about on this site....
Time to change company I suppose...

-G

Giorgio
Boston, Massachusetts