This detailed account of the issue, and the service credit, are two reasons I am a VOIPo supporter. Note that supporter does not equal 'fanboy'... I won't recommend VOIPo to everyone (as you might notice on BBR), but it's a solid service for anyone who's considering VoIP at all.

In all honesty, I would not be surprised to see issues come up like this again over the next few months as your systems and processes (not just hardware/software, but policies, etc) are put into practice and you learn what works and what doesn't. If you continue to tackle problems as you did this one, you have a bright future ahead.