The Feng-GUI Service Level Agreement published.
The agreement guarantees 99.9 percent availability of the service within a region over a trailing 30-day period. If Feng-GUI Services fails during that time, or doesn't meet the agreement, businesses get credit back.
"... the Feng-GUI Covered Services web interface will be operational and available to Customer at least 99.9% of the time in any calendar month (the "Feng-GUI SLA"). If Feng-GUI does not meet the Feng-GUI SLA, and if Customer meets its obligations under this Feng-GUI SLA, Customer will be eligible to receive the Service Credits described below."
"If the Monthly Uptime Percentage applicable to the month of such request is confirmed by us and is less than 99.9%, then we will issue the Service Credit to you within one billing cycle following the month in which the error occurred."
here is an example of an email sent from Feng-GUI support to a customer, with a credit back notification.