Coinbase may refund unauthorized transactions if reported promptly. １ー（８７７）ー５４７ー９０４０ Contact their support team immediately and provide evidence. For unauthorized bank or card transactions, you can also １ー（８７７）ー５４７ー９０４０ dispute the charge with your １ー（８７７）ー５４７ー９０４０ bank or card issuer for potential reimbursement.