Kat Farmer had this same pickle with her last holiday. If I remember correctly, they were given a discount in exchange for the holiday company to use her photos as publicity. Or similar.
So it wasn't paid for, as they still had to pay for everything else.
In the end (after much questioning by people) she just basically said "we got a discount for this but paid for everything else"
It's a bit unwieldy but it's as clear as day.