S.S.
Your best bet would be to send your complaint in writing to:
Tom Wilson, CEO
2775 Sanders Road
Northbrook, IL 60062
Tom has an entire department dedicated to resolving customer issues. This department takes complaints much more seriously than any Allstate manager would. They also include a deadline for the complaint resolution by the agency force so rest assured multiple managers will look into your complaint. Make sure you include your policy number(s) and good contact number. By going this route, every level between the top (Tom) and the bottom (agent) is aware of the complaint. This includes any market-level managers, regional managers and sales vice presidents.
Good luck with this!