Hi, the good condition bonus during Covid was upped to £600, you received £35o early as part payment of the GCB. You would then have received a payment of £250, if you had had taken a new lease out after 3 years, but, because you extended your lease to 4 years 5 months, you have received an extra £100, which is correct, as the GCB is not paid on a pro rata basis.
You would have then received £750 new vehicle payment, ether into your bank account ot taken of the AP of your current car.