Apple has fired back against claims by the maker of the Fortnite game that its control of the App Store gives it a monopoly.
In a response to the August lawsuit filed by Epic Games, Apple called those arguments "self-righteous" and "self-interested".
It denied that its 30% commission was anti-competitive and said the fight was "a basic disagreement over money".
Apple also said Epic Games had violated its contract and asked for damages.
The filing is the latest in a legal battle that started last month, after Fortnite offered a discount on its virtual currency for purchases made outside of the app, from which Apple receives a 30% cut.
In response, Apple blocked Epic's ability to distribute updates or new apps through the App Store, and Epic sued, alleging that Apple's App Store practices violate antitrust laws.
The court allowed Apple's ban on updates to continue as the case plays out, but the existing version of Fortnite still works, as does Epic's payment system.
Apple had said it would allow Fortnite back into the store if Epic removed the direct payment feature to comply with its developer agreement.
But Epic has refused, saying complying with Apple's request would be "to collude with Apple to maintain their monopoly over in-app payments on iOS."
In its filing, Apple said Epic has benefited from Apple's promotion and developer tools, earning more than $600m (£462m) through the App Store.
Apple accused the firm, which it noted is backed by Chinese tech giant Tencent, of seeking a special deal before ultimately breaching its contract with the update.
"Although Epic portrays itself as a modern corporate Robin Hood, in reality it is a multi-billion dollar enterprise that simply wants to pay nothing for the tremendous value it derives from the App Store," it said in the filing.
The legal battle between the two companies comes as Apple faces increased scrutiny of its practices running the App Store.
At a hearing in Washington over the summer, politicians also raised concerns that Apple's control of the app store hurt competition.
The European Union is also investigating whether Apple's App Store practices violate competition rules.
Apple has denied those claims, arguing that its App Store has made it easier and cheaper for developers to distribute products.