How do you get an excess baggage of 140kg on board our flight to Nadi from Christchurch?

Freight consisting of donations of children’s storybooks and school readers, biblical textbooks, clothing material, medical equipment, stationery, and five sewing machines, all boxed up, ready for dispatch.
Now to ‘somehow’ get these 11 boxes through check-in.
“I know what you’re doing. I know what you’re up to” were the words from the check-in lady as she eyed us up.
“I’m not religious myself, but there are missionaries in our family. And, my Aunty is a really good Christian, she would be so proud of me if I helped you out”.
45-minutes later, somehow, miraculously, ALL, yes all 11 boxes, 140kg of excess baggage were assigned and dispatched for our flight to Fiji.
No charge.