Early discount on Purchase invoice

Hi all,
We always received discount from supplier on early payment. The discount is not stated in the invoice but supplier will issue us their credit note after received payment from us.

What we doing now is we key in purchase invoice in full amount, but we make payment entry only according to the discounted amount.
Then we create Journal entry to debit creditors and debit “Discount received”. Im not an accounting person, I hope I got this right.

However, all the purchase invoice that I created payment entry are still shown not fully paid.

Any suggestion a better way to this beside cancelling and creating the purchase invoice?

Thanks and regards.