How to generate a customer ledger with adjustment amount?

Hello!

Basically i have two queries-

1. I have a customer who paid for the products that he purchased from my business. The customer who purchased a number of products from my business made payments with adjustments due to marketing expenses that the customer provided. Now, when i am making the entry of the amount received, it gets adjusted to multiple invoices associated with the previous orders. But i want to do the manual entry for each payments with a selected payment type, either its a marketing expense, advance payments or any other type of payments that may require. How do i do that?

2. Following up on point 1 - i tried to make manual ledger entry and creating expenses by adding marketing expenses, but the amount does not get adjusted in the customer statement. What can i do to make a manual payment entry and have it displayed under customer statement with specific annotation for that amount?

Thanks,
iOOTE.