I had a transfer cancelled for the same reason and it was indeed my fault for not hearing my phone ring all morning while they tried to call and authenticate my identity, so they cancelled the transaction and refunded my card.
I tried again and did answer the phone and that went great. Then they said that More Money was requesting a government issued ID from me and that they were uncomfortable sending it. So as they requested I just wrote a letter on word authorizing them to forward my drivers license (scanned into a PDF) to MM and that they weren't liable. My transfer was completed minutes after that.