Inbound call centres are centralized offices which are operated by modern organizations to administer incoming product supports or information inquiries from consumers. In this paper, an improved model for an inbound call centre was developed using Hierarchical Timed Coloured Petri Nets (HTCPN). The inbound call section of Federal Road Safety Corps (FRSC) in Abuja, Nigeria was used as a case study in developing the model. The developed HTCPN model is made up of six (6) modules conceptualizing call distribution processes taking place in the centre, these areas; Call Arrival, Processes, Hang up, Major Call, Minor Call and Enquiry. These modules modelled the dynamics of call classification, queuing and termination under overload conditions. By combining places, transitions, arcs and timed tokens, the HTCPN framework provides a structured, hierarchical representation of call flow processes. The developed HTCPN model can be easily modified through it associated modules to suit any future modification in the considered process or other related ones.