How can you combine Credit Control / Collections with good Customer Service?

 customer service  allows clients to reduce costs & improve customer ... customer satisfaction in areas such as customer contact, billing, credit control and e-fulfilment. ... 

The collection need customer service skills on the receivable following up.

Yes you can and you should.
Collecting is a very negative and unpleasant experience, customer service should be there to remove at least part of the shame.
I have worked at a debt collecting company, so I've been there and done that.

Credit control is to be mitigated at the time of lending services or products.
Good credit controls ensure higher probability of recoveries and collection.
Good customer services during or after sales further assure the recoveries.
Also good customer services reduces the probability of dispute during process of collection.