The Twilio billing system experienced an anomaly on July 18th, 2013, causing erroneous credit card charges and account suspensions for approximately 1.1% of customer accounts. The issue was resolved by the on-call team, with service restored to all affected accounts by 6:24am PDT/1:24pm GMT, although a brief re-occurrence occurred later in the day. To make up for the inconvenience, Twilio is crediting affected customers an additional 10% of their last 30 days' spend and refunding erroneous credit card transactions, as well as making those who incurred overdraft or over-limit fees whole. The company acknowledges that its response was not satisfactory and is committed to providing better quality service in the future.