Managing iCloud storage after syncing MacBook and iPhone messages

hey all, i have a mac and iphone and originally just had messages in icloud on my iphone switched on which took up about 2.5gb of icloud storage. I decided to sync my mac messages to icloud as well last night (all the messages were the exact same) and once it finished my messages took up double the storage now. Not wanting this i switched off messages in icloud again on my mac however my storage has t gone back what it used to. I contacted apple support last night and they couldn’t give me a clear reason why my storage doubled when i synced my mac to it and i got told to wait 24-48 hours to see if it updates in my storage now that ive turned it syncing for my mac. I was wondering if anyone had any clear solutions or advice thanks!

[Re-Titled by Moderator]

Original Title: issue with imessage syncing