The tug of war between Spotify and Apple has intensified, with the Swedish music streaming service now calling Apple a "monopolist".
Taking exception to Spotify's complaint with the European Union (EU) last week alleging iOS App Store rules to be unfair, Apple slammed Spotify for wanting "all the benefits of a free app without being free".
According to a Variety report on Sunday, Spotify said that "Apple's response to our complaint before the European Commission is not new and is entirely in line with our expectations".
"Every monopolist will suggest they have done nothing wrong and will argue that they have the best interests of competitors and consumers at heart," said Spotify which entered the India market in February.
"This is evident in Apple's belief that Spotify's users on iOS are Apple customers and not Spotify customers, which goes to the very heart of the issue with Apple," it added.
Earlier, Apple hit back at Spotify for its anti-trust complaint with the EU.
"A full 84 per cent of the apps in the App Store pay nothing to Apple when you download or use the app. That's not discrimination, as Spotify claims," Apple said in a statement.
In its complaint with the EU, Spotify said that Apple requires it and other digital services to pay a 30 per cent tax on purchases made through Apple's payment system, including upgrading from a free to premium subscription.
According to Spotify, if it pays this tax, it would force it to artificially inflate the price of its premium membership well above the price of Apple Music.
Apple replied, saying its revenue share is 30 per cent only for the first year of an annual subscription. It drops to 15 per cent in the years after.
"The only contribution that Apple requires is for digital goods and services that are purchased inside the app using our secure in-app purchase system," Apple added.
The Cupertino, California-headquartered tech giant also alleged that Spotify was trying to squeeze the artists, musicians and songwriters, not just the App Store.