Ticketing and Agent management

We would like to make online ticket creation module:
– Users can login and create a ticket.
– Admin can see those tickets and process them/edit them.
– Admin will select a vendor (a agent) to which he will assign that ticket.
– Vendor gets email intimation – and ticket is assigned to that vendor.
– Vendor manages that ticket and updates it further.
– Admin then updates the ticket to show users.
– Users can see the history of all ticket applied etc.
– Admin has rights to add new vendor and other vendor database management.
– Can you suggest a plugin for such vendor and ticketing management please?