the most likely/frequent meaning:

specijalista za naplatu potraživanja / referent za naplatu potraživanja?

"Collections Specialist

Key Responsibilities

The duties of a Collections Specialist include collection calls and/or correspondence in a fast paced goal oriented collections department.
Providing customer service regarding collection issues, process customer refunds, process and review account adjustments, resolve client discrepancies and short payments. Responsible for monitoring and maintaining assigned accounts- Customer calls, account adjustments, small balance write off, customer reconciliations and processing credit memos.
...

Essential Functions

Weekly and monthly reporting to direct supervisor
Monthly Delinquency notices
Processing monthly credit memos and the appropriate reporting
High volume phone calls to assigned delinquent customers
...

Required Skills

3-5 years High Volume corporate Collections experience.
Knowledge of Billing and Collections procedures
..."
[http://www.accountingjobstoday.com/cm/Job-Descriptions/colle...]

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Note added at 9 hrs (2013-08-19 00:29:53 GMT)
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zapravo:

specijalista za naplatu zakasnelih potraživanja