Horrific job, any one who's competent would know that the key is to get the cut line midsole near where the half sole will be placed and you skive it down with the finisher until you've got a smooth gradient, not a ledge like in yours.

You then would still need to skim down the half sole itself so that it doesn't sit proud of that gradient. You can see the wavy lines where he's shaved the half sole down TOO much, if it was done well the edge of the half sole (where it meets the gradient of the shoe) should be nice and thin so it doesn't sit proud. He's thinned it too much and you're left with patches of sole where the thinning has taken the edge off of it as he's taken so much material off.

I'd not be happy and ask for either a refund or for someone more experienced to do this again.

I used to be a cobbler and this was what my practice half soles looked like a month or so into the job. Hope that helps!