Oh, that's difficult. I think I would feel similarly, but thoughts and feelings aren't always accurate. Do you think you could come up with some alternative thoughts about what might have happened?
For example, it doesn't seem like there is any evidence to suggest that there are cameras or that the workmen were spies. Perhaps, due to organisational lack of communication, the council forgot to tell you that the workmen needed to fit other things. This happens often, unfortunately, and sadly doesn't take into account how anxious that could make a vulnerable person feel.
What I would suggest is contacting the council to ask why this extra work has been done. It might alleviate some concerns. I definitely wouldn't dismantle anything because that could cause you harm. Instead, if this worry persists over the next day or two, I would suggest contacting your CPN as she could probably help you a lot.