Commenting System with Admin Area

Hey, what i need ist. When anyone Order on my Shop by my Payment System [login to view URL] Than in want that script what you programm make a Ticket Open in the Admin Area. Also the Buyer get a massage with the lOgin Details for the buyer Area. In that Ticket i can corespond with the buyer (Commenting System looklike Wordpress or so). Additonal i want that the User get all Time when i respond a Massage to his Mail. All Time when an order will bin created a new ticket will opened. When the Problem is solved 5 days later the Access will be removed from the buyer but the ticket does not been delated. i dont know how much that cost so i only set a placeholder by Payment Budget