How to download saved messages from icloud?

iCloud syncs messages across your devices. It does not backup messages over time. Any message available to you in iCloud is also already on your device.

If you delete and disable, you are effectively turning off iCloud and erasing all of your message data that resides in iCloud to allow syncing to happen.

What device are you looking at messages on? It can be very hard to look at older messages on an iOS device, even though they are there.

If you want to archive messages from an iOS device, try the application iMazing. It's available for both Mac and Windows. You should be able to download everything and review it easily.

What I'm saying is we don't know if they're missing or if you simply can't access them. It has been my experience that the Messages app stalls out if you try to go back too far.

If they are there, which I think is possible if you've got it set to "Forever", then an application like iMazing will be able to download them from your phone. I don't think there's any way to know until you try, though.