Two ways in, both reaching the same team.
The chat widget in the app, at the bottom left. Fastest, because it comes with your account attached.
Email [email protected]. Better if you need to send a file or a long explanation.
We usually reply within a couple of business hours. Weekends are slower.
What to include
The first reply is more useful when we can see what you saw.
Say which workspace it is, if you run more than one. Say what you did and what happened instead of what you expected. If there was a message on screen, quote it exactly, because the exact words tell us which part broke.
A screenshot is worth several paragraphs. If it happened in a chat, the link to that chat is better still.
Billing problems
Send these to either channel and say billing in the first line. Include the invoice number from Settings, then Invoices if the problem is about a specific charge.
Refunds have their own rules, in Refunds.
Reporting something broken
There is a Report a bug item in the user menu in the sidebar. Use it when something is wrong with the product rather than with your account, and include what you were doing when it happened.