They started questioning us and assumed we had pirated the font. Send them the old receipt and told them politely to fuck off.
Never heard of them again luckily.
Marketing got very nervous though and wouldn't calm down, so I sent the receipt.
It turned out we had got licences, but not for anywhere near the billions of pageviews we were putting through.
We quickly switched the fonts to open source analogues and got the legal team involved. The final bill was much less than their opening bid but still a lot. It would have been much more expensive if we hadn’t had the resources to negotiate.