Because many/most of us never receive a response, or at least not a timely response, from the airline. I'm waiting, 21 days later, to hear ANYTHING (beyond the immediate autoreply) in response to a refund request. The refund (for miles+copay UG) was supposed to happen automatically at the time UAL didn't provide the service I had already paid for, April 20. The very helpful "check refund status" tool on the website? "No record of your request, why don't you try faxing it in." I think I'll skip that and try the CC dispute now.