[londons_explore]

oh there are - billing systems at scale almost exclusively work on logs. Logs can take minutes or hours to aggregate and transmit to a central place.

Ever notice how your "1GB" data plan sometimes lets you use 5GB if you happen to be roaming in another country and downloading something fast over 5G...? Same reason.

[oaiey]

They are also checking your account .. and as easy as you can lock an account, as easy you can soft lock it via a flag because the billing system says enough. And the few cents in between they swallow easily (as with so many other inaccuracies).

They do not want it, that is the only reason.