Originally Posted by Waggy

On the flights you booked 3 weeks ago where the vouchers don’t seem to have been used have you:

• had the payment taken from your credit card for the extra tax due when you added the return flights and had the avios debited
• checked you have bagagge allowance on your return flight doesn’t say “zero bags”

it may be that the return flight hasn’t been added properly to your outbound booking or it has and you’ve got lucky and managed to keep both your vouchers!!