It's more likely that the "winners" would sue the lotto company for false advertising, breach of contract, and mental distress, and force a much larger settlement - possibly 1000x what was offered ($200k in my example). They might even force the company into bankruptcy. But that option isn't available to poor people in places like the Philippines.

The "multiple winners" thing "makes no sense" to you because you're looking at it from Pepsi's perspective. Not from the perspective of someone who thought their life was going to be transformed, and now it's not. Their thought process is more like "It's not my problem if the people running the lottery screwed up. I won fair and square according to the rules that were set out. They have to pay and that's that."

Pepsi marketed the heck out of this thing, gained a ton of market share, and would stand to make lots of money even after their ultimate $20 million bill. But instead they reneged on a contract by blaming it on a technical error. I don't understand why you're so eager to let them off the hook for this - don't contracts mean anything?

> the alternative being having a new ticket issued for free

There are plenty of other alternatives actually, all the way to "Pepsi actually pays the $32 billion, in installments". But that's not realistic - they'd probably just exit the Philippines market instead.

Here's a more realistic alternative that might have gone over better: Pepsi says, "We get that a lot of you bought Pepsi because of this promotion and we feel terrible. To make it right, we're upping the prize pot to equal all of our sales in the Philippines this year. After all, the only reason we made most of those sales was because of the prize, so we're gonna forfeit those."