First, a collection call center is a call center which will help a company remind debtors of the need for them to pay their debts and when. The call center may also act as the collecting agent as well, meaning the call center has authority to collect debts on behalf of the client company (or the company to whom the debts are owed to.) A collection call center customer service representative is necessary when a personal touch becomes more persuasive than just a static letter.
Some debtors are actually good payors who may have simply forgotten about the debt and the letter sent to remind them about the debt, meaning one phone call from the customer service representative is all it takes for them to be prompted to pay up already. However, some debtors are poor payors so that is where the collection call center becomes a necessity.
This does not mean a collection call center and its customer service representatives have a great degree of power over the debtor actually, the debtor should always be treated with professionalism and courtesy by anyone who calls (whether the call comes from the collection call center or the actual company to whom the debt is owed to) because there are laws protecting debtors from any form of harassment related to the debt. This is why the collection agency (like a collection call center) has to thoroughly document the actions they have taken to contact the debtor and any response that debtor made regarding payment.