"It is kind of similar to a story I have seen here on HN about Hertz (car rental company) having sued Accenture for a botched project that was supposed to help them improve the business’s website and to create mobile apps."

The main idea is that you sign a contract for some services in exchange for cash. And if the services are not provided, you don't need to pay the cash.

Depending on who has the advantage, (whether the contract was paid upfront or not), one party or the other can bring it to court, and similarly the other party can counterclaim.

In both cases the claim will be for "Breach of Contract". In my experience there is no expectation both parts of the contract have equal weigh and requirement for proof. It's not like you automatically win a case if you signed a contract, you need to show that you did the work, that client received what they asked, that you made no fraudulent representation to get them to sign. It's not as straightforward as, "they signed for 50K, therefore they owe 50K"

Of course this can be solved extrajudicially, through internal processes, but in general these processes follow the same logic as the courts of law (common law in this case), so the underlying legal case law is what shapes these refund policies.

IANAL