First, the artist shouldn't have ignored you all this time. Nothing excuses them for ignoring you.

Second, I think you were being incredibly impatient. Once payment is received an artist doesn't drop their entire life to devote themselves to your commission. One week in an they're already getting passive aggressive comments on their journal? Yeesh.

Lastly, not only are you getting your money back for the unfinished commission, which is fine, but you're also getting your money back for what they did complete. Did you ask for a refund for the remaining piece? =\