An arbitrator will contact you via the dispute chat and help work through the trade with you and the other user. This chat is in a separate box, and all messages are between you and the arbitrator only.

An arbitrator may ask for:
Proof of purchase (e.g. a screenshot showing your payment)
Proof of having not received the funds (e.g. a recent statement)
Proof of ownership of the account
Any confirmation e-mails regarding payments
Anything else that will help an arbitrator make the correct decision
I reported another user but haven’t heard a response.
We inspect the trade and the reported user, and we may take action by suspending the account. It prevents the user from opening new trades, and nullifies their feedback, both given and received.