Write some Software

I need a wordpress plugin with below simple features: 1. Basic idea is customers must be able to create "text based" support tickets, provide severity (Sev 1, Sev 2, Sev 3) and attach any file in case needed. 2. The plugin must allow existing users to auto access support ticket. There are only two roles on support ticket plugin (Client, Worker) 3. Ticket comes to general Bin and then we assign a worker to it. Worker puts his comments and user is notified via email everything there is a change in support ticket. 4. Worker must be able to close the ticket once issue is resolved. 5. A user must only see his tickets or can raise a new ticket.