Q: I've bought 50G iCloud space, never successfully got a back up since but now it says 25.3G left? Help please

HI there!

not sure what's happening but I've never seem to be able to successfully back up my phone since i bought 50g of iCloud space.

ive tried to back up several times but they have failed and im not sure it's because of my 9k photos or iOS issues.

that said, if I can't back up, how is it my new storage space being reduced to 25.3g since I've never been able to back up (it said back up was never done)?!

its killing me because I have been reading so many FAQs but can't seem to troubleshoot

please help! Thank you in advance