I am not sure that I understood your question entirely but based on my interpretation I would suggest taking a deep look at Teamwork. (https://www.teamwork.com/) Teamwork is a software platform designed to help organize a company and help it manage tasks and projects. The Teamwork package consists of 3 products.

Teamwork Chat - This similar to slack minus a few features. Teamwork Chat includes a direct integration with the rest of the Teamwork system. This allows members of your company to communicate in real-time, create rooms, and share project details all in a permanently recorded environment.

Teamwork Desk - This is a great ticketing system that allows external parties to have tracked email communication with reps. This may be the avenue where you deposit incoming inquiries. Your brand management reps could get the inquiry via desk and then turn it into a variety of tasks for various departments in Teamwork Projects. As tasks are completed they can use Teamwork Desk to communicate back to the customer. This software includes a portal where these reps can log-in and see their entire account/request history with the organization and a help desk that would allow you to create self service help docs for your products/services/store if necessary.

Teamwork Projects - Teamwork Projects is a project management software that allows you to create users, departments, and even allow client access into the system. You can develop projects, tasks, timelines, and calendars based on those elements. You can easily send tasks into Teamwork projects from desk and then route communication back to desk as projects are completed.

Overall, it sounds like this would be a great combination of tools to help you manage your products and brand. I am not a representative of the company nor do I get paid for this recommendation, in fact, I pay them as a user and I use these tools to accomplish something very similar at my company. They have some great videos. Check it out and see if it would be a good fit.