I might be wrong but from my experience the billing schedule detail, split out by future date, doesn't exist in the system as data. From my tackling of this issue before the system only knows the billing frequency, next billing date, and remaining bills to be generated and uses that data to present the full schedule by date to a user on the UI. What you see on the billing schedule tab in the UI isn't living in the system in that format, so if that is what you want on the report, you're probably out of luck. I've never been able to get to it natively. It would be possible with SuiteScript but that's a whole other thing.
Happy to be corrected on this though