There was a global outage on July 15th.
http://www.crn.com/news/applications-os/300077459/microsoft-experiences-global-office-365-outage.htm
Give the billing department a call or open a ticket up online and it should only take 15 minutes or so. I have a prepaid account and at first they said they were just giving me a credit for 2 days. I pressed back and said it should be for 25% of the month and they increased it to 7 days (no explanation on why they tried 2 days at first yet).
http://www.microsoftvolumelicensing.com/DocumentSearch.aspx?Mode=3&DocumentTypeId=37
“If the Monthly Uptime Percentage falls below 99.9% for any given month (43 minutes of downtime), you may be eligible for the following Service Credit: Monthly Uptime Percentage Service Credit < 99.9% 25% < 99% 50% < 95% 100%”
For those who were impacted by this outage the refund is clearly not worth much but if...
< 99.9% 25% < 99% 50% < 95% 100%”