I was moving messages between some mailboxes (imap), and something went wrong and the mailboxes disappeared, I'm pessimistically assuming that they won't come back, but as additional annoyance I've been having issues with emails received since then undeleting themselves.
Reading between the lines here, would be be correct in understanding that you are using an email client on your PC or some other device, rather than webmail?
Deleted emails reappearing sounds like you are doing bulk deletions and they are failing. "Deletion" is a multi step process unless you hold down the SHIFT key when pressing delete. Delete is actually a move from wherever to the deleted items folder. Generally the email client hides the deleted items in the original folder and them moves them in the background. If that move fails due to a server time out, they reappear where they were.
Best to check the actual content of the mailboxes using webmail, though at time its performance can be sluggish.
You can mitigate what you see happening by...
Increasing the server time out period (say 2 minutes) in your email server settings