How are calls charged in call centre campaigns?

The charges in a call center campaign are as per the following parts of a call:
1. Agent connection type ( A-leg)
2. Outbound call to the destination (B-leg)
    - Patch through calls ( S-leg )

Agent connection type ( A-leg)
The agent connection type can be  - 
a. Browser
b. Phone
c. Phone ( dial-in) 

Each connection type has different pricing as per the country to which calls are made. Charges as per country can be checked from here.

Outbound call to the destination (B-leg)
This is the actual call made by the agent to the destination after getting connected to the campaign. The pricing again depends on the country the agent is calling to. The country-wise pricing can be checked from here. 

Patch through calls ( S-leg ):
In a call center campaign, when the agents connect to a senator through patch through calls, then another leg of the call is created, the pricing of which again depends upon the country to which the call is being made. 

Thus, Total cost per 1 minute = Cost of agent connection ( A leg )  + cost of the outbound call to the destination ( B leg ) + cost of the patch through call, if any ( S leg).

Incoming calls pricing: 
If a contact calls back on a number you rented from CallHub, you can transfer it to any landline or cellphone number of your choice. The pricing of the same would also be based on the country wise incoming changes which can be checked from here.