Where have my Notes gone?

My son uses my iPad to play games so I took off personal stuff I didn't want him reading or accidentally editing. Part of that was my Notes and Reminders, so I turned off sync to iCloud first, then deleted the apps and data. The assumption was that that would prevent the deletion from syncing to iCloud and thus to all my other linked devices. The next time I opened my Notes and Reminders on my Mac, they are completely blank. No entries at all. I grab my iPhone - the same thing. I log into iCloud - nothing for Notes or Reminders, not even a 'recently deleted' folder and nothing relevant in the Data Recovery section.

I checked my iPad again - sync is still off. I had important Notes and shopping lists and I can't be losing them. I tried restoring a local backup saved to my Mac from before the deletion, which still came up with blank apps.

After many hours of frantically troubleshooting & Googling, I contact Apple Support. They take me through all the basic troubleshooting that I've already done, and said they'll have to get a senior advisor to ring me. When he rings, he takes me through more checks, even remoting into my iPhone to check settings. He ends up saying he has no explanation and that even on his side there is no record that any Notes or Reminders were even saved to iCloud. I'm like, well obviously they were there as they were syncing to all my devices beforehand, and I asked, surely they wouldn't have synced the deletion from my iPad if I turned the sync off first? He said that shouldn't happen. He also said that if the Notes and Reminders were backed up to iCloud, a backup restore wouldn't restore them. He said he'd have to check with the engineers if they can see anything or have any way to restore the lost information.

In the meantime, I used a third party app (iMazing) to look at the iPad backups I had saved on my Mac and I can I see the missing Notes in the backup. I can use it to restore the files but to restore them all I'd have to pay $80 for a year's subscription (I can restore 5 for free in the trial). But why should I have to pay when this is an Apple issue?

The senior advisor called me back today to say they still have no explanation about what happened and that the engineers can't see any sign of any of those files being stored in iCloud and that they don't have a way to restore them. I told him that the third party app can see the missing Notes in the backup file and asked if they have a tool I can use to extract those files or if I can send them the backup and they extract the missing Notes for me. He said no, they have no tools to do such a thing and he doesn't even know how the third party app can do that.

So basically, I have lost my important data, Apple have no explanation about how/why it happened and no way to restore it even though a third party has software that can do it. I am totally shocked and aghast that this company, to whom I pay a lot for their products (they're not cheap) think that it's acceptable to resolve an issue by basically saying 'we don't know why and we don't have a solution, too bad for you, sorry bye.'

Does all this sound legit? To be honest, I lost a lot of faith in this 'senior advisor' when I had to continually correct him when he kept referring to the device in question as the iPhone when it was the iPad that was the start of all this. Plus he kept telling me that there wasn't enough space on my iCloud account to backup my entire iPad, as if I was lying, when in fact I'd only backed up certain things I wanted to sync to my other devices (the 'whole iPad' backups were saved locally to my Mac).