As fun as this thread is, that skimming is absolute dog s**t, and I would seriously doubt he is capable of correcting it. Its not even skimmed tight into the corners ffs. Refund or pay someone to fix, sadly is going to he the course of action. I sincerely doubt they are cabable of fixing it, if they patch it i reckon they will leave ridges trying to feather it in. I cant see them redoing the whole thing,which is probably what it needs. Someone already said, looks like a lab has had a wee go at being a plasterer. No one out there time and even remotely capable would leave a mess like that. Sorry, op, but youve been had.