Backblaze does not have an official Service Level Agreement:
We try to respond to every help request within 1 business day of it being received, and can often answer them more quickly.
Chat support is available on weekdays 9-5 PDT by logging in to help.backblaze.com and scrolling to the bottom, or the black tab on the left hand side.
If all chat agents are currently helping customers the chat window will not appear.
Our agents also take most major US holidays off.
Backblaze does not have phone based support.