Why is it that it takes 48 hours to update my international usage?

As a subscriber to the 500 minutes Verizon World Plan I find the practice of updating of the usage 48 hours after the making of a call highly suspect. My choices here is either risk going over the limit unknowingly  - and being hit with an excessively high charge - or not using all of the minutes that I am paying for! If my bank handled my checking account in this manner, I am sure the government would shut them down.

Each time a call is made  - international or not - the number called and the duration of that call is recorded. Why is it that the international account is not immediately updated right after that call? CableVision international plan does it! I know there is absolutely no reason - other than one to sucker the consumer into either going over the limit or to not use all the allowed minutes - why this updating cannot be done. I worked in IT for more than 50 years - computer operator, computer programmer, system programmer, data base administrator, network specialist - explain to me what is the limitation in your system design that prevent the immediate updating of the international usage account.