Can you correCt it please?
CusTomer service:
-Dealing with customer complaintS
-Replay of customer questions
-Helpdesk-assistance by use of products
-Extension of contracts, modification of customer data
Although - I don't understand 'Replay of' or 'by use of products'.
Can you explain a bit more what you mean by these, and we can tell you if what you have written is in fact correct.