Open the listing and jump to Report. Use Report this listing or Report this seller. That opens a Safety case. Contact support is a different queue.
Search to find the listing first. Staff will never ask for passwords, OTPs, or bank PINs. mr.bid does not hold funds, so a report is not a refund. A copyright or intellectual-property notice is a different form on the Copyright notice page. That is not a United States DMCA takedown.