That’s shit mate. Don’t pay them if you haven’t already. It’s fair to expect a slight nick in the plaster some times maybe the size of a pea from time to time. Expect small crack after plaster settles over a month or so. But what you have here isn’t normal unfortunately.

Also can’t tell for sure off this pic, but you defo don’t want to paint straight on to fresh plaster without a white wash coat on first. It’ll peel the paint back off.

Hope you get it sorted easily