A2Billing (ePayment configuration - stop auto-refill)

We have a A2Billing with Paypal payment installed and testing all fine. Default, while the ePayment (paypal) transcation is completed, it will auto_refill the customer account. We would like to have a manual topup : - epayment completed, same as normal that recevie payment information and create "Billing > Payments" entry. - Stop auto_refill for this transcation. Service provider must well known A2billing system and requires providing details information for guide us to modify our configuration untill complete testing. All other function cannot be affect by this. Payment will place escrow.