Re: "I was trying to free up space on iCloud and deleted voice memos stupidly assuming they’d remain on my phone - they haven’t and I’m devastated"
As you discovered, deleting synced items from either iCloud or device, deletes them from everywhere that is in sync.
Apple suggests we archive copies of everything we store in iCloud:
Archive or make copies of the information you store in iCloud - Apple Support
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Re: "How I can i get all those deleted voice memos from icloud ?"
Try looking in the "Recently Deleted" folder on iPhone... deleted items are generally available for up to 30 days, so you can likely restore them to where they were deleted from.
See:
Apple Support's online article, Edit or delete a recording in Voice Memos on iPhone - Apple Support
Eg: says:
"Deleted recordings move to the Recently Deleted folder, where they’re kept for 30 days by default.
To change how long deleted recordings are kept, go to Settings > Apps > Voice Memos > Clear Deleted, then select an option.
Recover or erase a deleted recording
- Go to the Voice Memos app
(in the Utilities folder) on your iPhone. - Tap the Recently Deleted folder, then tap the recording you want to recover or erase.
- If you don’t see the Recently Deleted folder, tap
at the top left. - Do any of the following:
- Recover the selected recording: Tap Recover.
- Delete the selected recording: Tap Delete.
- Recover everything in the Recently Deleted folder: Tap Edit above the Recently Deleted list, then tap Recover All.
- Delete everything in the Recently Deleted folder: Tap Edit above the Recently Deleted list, then tap Delete All."
If needed: Tips on making space available in iCloud:
Manage your iCloud storage on your Apple device - Apple Support