Transporter bill settelment entry

i have a query on how to do entry after settlement of bill of transporter.
 suppose a transporter issues me a bill of 60000,
i make a entry as :
carriage inwards a/c dr.... 60000
to x transport pvt ltd 60000
but when the bill is finally settled for say 56000,
then how to make the entry for the balance 4000 after making the payment entry of 56000?
1.will it be discount received 4000 or
 2. i shall make a reverse entry    as.....of x transport pvt ltd a/c dr....4000 to carriage 4000