Dropbox hasnt deleted them, sorry. Something else has.
If you can see that the files are deleted on www.dropbox.com/events then that is NOT Dropbox which has done it - Dropbox doesnt do that. Somebody/something else has. Dropbox would close an inactive account completely if its not used but wouldnt do a deletion like that.
If they are showing on events as deleted then they've been deleted from a connected device/the website. Note that its simply not possible to get them back via Dropbox I'm afraid - you'll need to see if they are on any connected devices or via any backups you have.
- - - -
Did this post help you? If so please mark it for some Kudos below.
Did this post fix your issue/answer your question? If so please press the 'Accept as Solution' button to help others find it.
Did this post not resolve your issue? If so please give us some more information so we can try and help - please remember we cannot see over your shoulder so be as descriptive as possible!