My question is if i have say 10 invoices which are unpaid, The customer asks me to send a detailed statement where all transaction (with details) are mentioned. @tut
That is not an accounting function. That is customer relationship management (actually debt collection). A letter requesting payment is more appropriate, with copies of all overdue invoices showing the OVERDUE stamp. (For that, you must have entered a due date.) To me, it just sounds like your customer is stalling.