I have two of these 1040s. Clients do not answer emails or letters, so I have to assume they screwed me and went elsewhere or filed on their own using returns prepared by me. 

In on case I have a signed engagement letter, so since we signed it I can sue them to get paid, even if I don't ultimately e-file their returns. That was completed March 5, so I have no clue.

I cannot e-file without their approval.

[Edit] Interestingly, the IRS' Where's My Refund site said that the exact amount of the refund I calculated was applied to prior debts. But I didn't e-file it.