Is it normal for roofer to work on your roof without any notice?

New property. Last month or so we reported an issue to the developer about a possible gap/hole/misalignment on the roof. They only acknowledged our email and didn't say anything else. A month later, I was home by myself and suddenly hear someone walking on the roof, at first I thought maybe it was a thief then came the loud sounds of machinery (saw/grinder?) I'm glad that they finally sent someone over to fix the issue but I feel like it would be nice to be informed beforehand. From previous experience with the developers, they also don't tell you anything after an issue is resolved - what the issue was, how did they fix it. Is this all normal? Or should I be able to 'demand' more from the developers? I just don't want to be scared shitless next time, and be in the loop about what they chopped of or replaced etc.