Duplicate Call vs Repeat Call
A duplicate call is a call that was routed to a Call Endpoint (Buyer) in the same Conversion Group it has previously converted in during the De-dupe period designated in the Conversion Group on your campaign.
A repeat call is a caller that recently returned to your campaign using the same tracking number. The Toggles on the Campaign for Repeat Caller Handling dictate how repeat calls are handled. A call can be a labeled a repeat, but not a duplicate if it is going to a Call Endpoint (Buyer) that is in a different Conversion Group.