iCloud storage shows backup data that cannot be purged/deleted

I was also submitting a bug report but was wondering if anyone else has experienced the same so I'm sharing this over here as well.

Summary:

A few weeks ago I started to get notified by Apple that my iCloud storage is almost full.

I took action and started to dive into this issue since I’m not using iCloud storage for anything other than backing up my devices.

Steps to Reproduce:

1. I contacted apple support earlier and a case # was created.

2. I was advised to create local backups and do a full sync of my iPhone and iPad devices using iTunes.

3. After successfully executing the previous step I have signed out from iCloud on all my devices : Macbook, iPhone and iPad

4. I have signed in on iCloud on my iPhone and Macbook using my apple ID. The storage data now showed that was using 2GB of backup data while no device is backing up data to iCloud anymore

5. I have turned on the iCloud backup on my iphone again it showed that my phone backup size is 373.5 MB while I'm still "using" 2GB of backup data in total.

Expected Results:

I'm expecting to have more storage available for backups.

I'm expecting to be able to see the backups that are taking 2GB of space.

I'm expecting to be able to flush/delete the old backup data.

Actual Results:

There seems to be old backup data which I cannot delete.

Version:

Macbook 2 GHz Intel Core i7, 10.10.4, connected to iCloud

iPhone 5 iOS 8.4 (12H143), connected to iCoud

iPad 3 iOS 9.0 (13A4293g), NOT connected to iCloud

Notes:

I've contacted apple support by submitting a bug report. Have not received a response yet.