The limitation of the various systems are obviously there and, believe it or not, a lot of work is being done to make things better, including the suggestions above.
But, in all fairness, we've done a lot to try and work around the limitations and to put various options on the table to be used, the first being on the right product in the first place. For MBB it's for sure Top Up for most though we have subs who insist on the contract options exactly because they WANT to go OOB, clearly with proper notification.
As someone posted above (DJ or Bern, I think), the issue is largely with education. If we can get customers AND sales agents across the various Service Providers to understand the pros and cons, a lot of the OOB problems would never occur.
1. Pick the right product.
2. Use the tools.
But as the technologies allow, we're implementing them. It's just not 3 week projects, however simple it seems on paper. Building and implementing a rating & billing system that serves millions of subs takes years. And we've been at it for a few already. Of course a few forumites who've set up a MySQL server on Linux believe it's easy.