Custom CMS

Please read the requirement carefully, and only share relevant work. I need a cms which will be used to keep track of cases. The CMS will be web based, i.e there will be a module for the admin to add users and their roles along with usernames and passwords. When the users login the first time, they will be required to change their password. There will be 4 kinds of users - National manager (NM), State manager (SM), City manager (CM), and city employees (emp). Each level of position is in the hierarchy i.e the NM has access to all the cases, the SM only has access to cases in their region, and the CM has access to only their city. The NM, SM, or CM can create a case and assign a emp from the respective region to the case. When they do so, the emp will receive an automated email. Any of the 4 positions can add notes about the case. Reports will be created about various things including cases per region/city etc or money spent etc, or cases open etc. Reports can only be access by levels, so NM can access everything, SM can only access their region etc. If you send me a quote, please tell me how you can do this, and your previous experience in doing this. If you haven't done anything like this in the past, or if you don't have any ratings on this site, please don't' respond. Thanks.