Spotify says Apple is using its App Store approval process as "a weapon." Apple says that claim is a load of BS.

In a letter sent to Spotify general counsel Horacio Gutierrez on Friday, Apple general counsel Bruce Sewell rebutted the streaming music service's June 26 allegations that Apple is “causing grave harm to Spotify and its customers” by rejecting a recent update to Spotify’s iOS app. "We find it troubling that you are asking for exemptions to the rules we apply to all developers and are publicly resorting to rumors and half-truths about our service," Sewell wrote in a letter obtained by BuzzFeed News.

Apple declined comment on the letter.

Spotify had alleged that Apple rejected a new version of its app citing "business model" rules. It also claimed the company insisted that Spotify use Apple’s billing system if it planned to sell subscriptions (Background: Apple charges a monthly fee of up to 30 percent for the use of that system; Spotify has long charged an additional $2.99 for in-app subscriptions to avoid that “App Store tax” ). Gutierrez characterized this as anticompetitive. “It continues a troubling pattern of behavior by Apple to exclude and diminish the competitiveness of Spotify on iOS and as a rival to Apple Music, particularly when seen against the backdrop of Apple’s previous anticompetitive conduct aimed at Spotify," he wrote.

Unsurprisingly, Apple strongly disagrees.

"Our guidelines apply equally to all app developers, whether they are game developers, e-book sellers, video-streaming services or digital music distributors; and regardless of whether or not they compete against Apple. We did not alter our behavior or our rules when we introduced our own music streaming service or when Spotify became a competitor," Sewell explains. "Ironically, it is now Spotify that wants things to be different by asking for preferential treatment from Apple."

And as for Spotify's suggestion that Apple is treading on dangerous, anticompetitive ground, well, Sewell doesn't seem too concerned.

"There is nothing in Apple's conduct that 'amounts to a violation of applicable antitrust laws.' Far from it," Sewell, writes after wryly observing that not only has Apple’s platform generated "hundreds of millions of dollars in incremental revenue to Spotify" but that the Spotify App currently in the App Store is still in violation of Apple's guidelines. "I would be happy to facilitate an expeditious review and approval of your app as soon as you provide us with something that is compliant with the App Store’s rules," he quips.