Patching back to breeze block?

Yes indeed,if so simply re plaster the hole. Either with interior filler or multi finish plaster, but there are stages to the process to get the fine original finish back.

Hi there. If you could please help by providing a picture of the area in question, I will be able to advise you on the solution to your problem with a 100% confidence

Yes shouldn't be a problem, make sure the surface your patching isn't loose and take any loose away, sbr the area. If its render then plaster, build it out with plaster or fine filler then do a finishing thin layer to get a nice even finish. Should it be plasterboard just pack it out with thick plaster or filler then a fine wetter finish layer, lightly sand it when completely gone off to get a perfect finish.