If the Council had the right address & didn't use it, it looks like incompetence. If you want to pursue this you could:-
1. Ask the Information Commissioner's Office whether this breached the Data Protection Act.
2. Make a formal complaint to the Council & pursue it to the Local Govt. Ombudsman on grounds of maladministration.
However, do you know for a fact that the Suffolk manager told other people about it? If not, it may not be worth the hassle. If he/she di tell, then you could raise a complaint within your company, but doing so would inevitably mean more people knowing about the situation than do now.
All in all it might be best to just write to the Council asking for an explanation and apology, and then put it behind you.