Hardwall on a ceiling - options?

[Miktea]

Had two guys that put hardwall on my ceiling (painted plasterboard, they've removed the flaky paint and pva'd). I'm not happy as obviously hardwall is not for plasterboards and it can come off. What can I do now to fix this? Overboard? Or can it actually be not that much of a problem and I'm worrying too much? Can multifinish be safely put on top of it?

Thanks!

 

[vinn]

If the board is firmly fixed then maybe leave it for a while - seasonal and c/heating changes might or might not affect it?
Live with it for a while (you could mist coat it) & then come back here.