So long story short, for a company trip booked via TA the booking was made with no luggage allowance on a light fare. So I've just discovered this and been into Lufthansa.com and purchased baggage allowance for the trip.

But it has not issued me with a receipt. So how do I get this as I need it for claiming on my expenses?

When I click on "Download your invoice" it shows my flights but with zero baggage allowance, and does not show the extra that I've just had to pay. Although my itinerary is now updated with the allowance (on LH.com but not on checkmytrip.com!)

Any ideas?