Make customizations to Arcadier based marketplace

We created a marketplace using Arcadier ([login to view URL]). The market place is a service based marketplace for consultants to offer services. The problem is that the default settings for the marketplace cause an issue that we want fixed. Here is the issue: A consultant can create two listings A and B. If a buyer purchases a session (1 hour) with the consultant with Listing A, then after the puchase that time slot will appear as booked and unavailable on listing A calendar. But in Listing B that same time slot will appear as available! But that doesn't make sense since it's the same consultant with the same schedule just with a different service offering. So we want to have all calendars be in sync across all listings of the consultant/seller. Another potential solution would be to limit the consultants to open just ONE listing and in it they could offer different options to choose from and the buyer could only choose one option. If you have another suggestion we are open to hearing it. The solution should be simple and cost-effective.