Double billing system form App Store for the same subscription

I have purchased office 365 through App Store on 22/05/2021. Initially, I got a purchase bill of $79.99 from Microsoft on 22/05/2021 and AED 279.99 billed on 23/06/2021 from Apple. I could not understand why the double billing system from both. I have reported through your support. Kindly support and refund the extra amount you have billed for the same