Invoice Payments categorization & Payment Gateway service charges

Invoice Payments categorization & Payment Gateway service charges

How do I settle/treat the following transaction categorization scenario in Zoho books?

1// I sell my services using a payment gateway to Customer A for Rs.100, Customer B for Rs.200 and Customer C for Rs.500.  Each of them is invoiced for the respective amounts.

2// Each customer pays via the payment gateway.  The Payment gateway settles each transaction separately and remits the payment to my bank account MINUS its service charges & corresponding GST.

3// At the end of the month, the payment gateway sends me a SINGLE bill for the 3 service charges.  There is a GST component included which I need to factor in for input credit.

Now, since the vendor (payment gateway) sends a SINGLE bill at the end of the month, how do I categorize each of the Customer payment against the respective invoices and also the payment gateway vendor bill ?