Hello,
Your project need the combination beetween CRM and PBX (VOIP). With you basic information, I propose as:
1) Multiple level user group (such as normal staff, manager, admin, and super admin) : CRM (Customer Relationship Management) will be control all your task. Each users has their own privileges and cannot access to other User functions.
2) The data cannot be updated if no call has been made : data reporting ( call detail report : time call start, time call ends, recording file, billing,.... All about call detail report )
3) We will use our own server + 4) We will subscribe our own IP-PBX for VoIP + 5) The system either web-based or standalone, but we prefer web-based : CRM and PBX will be installed on your server. You can manage PBX and CRM via web page. Therefore, you do need to know much about the PBX. Otherwise, CRM also be configured via web. Exporting or importing will be supported.
I'm glad to provide the demo for CRM so that you can go around and test the function, If you happy with small CRM ( CRM + PBX ), we can deploy on your server.
I'm looking forward to hear from you soon.
Rgds,
Vu Le