Import tickets from deactivated account. (even though they should all still be there)

We had a Zendesk account with over 5000 tickets. We deactivated that account, but we exported all CSV, JSON, XML data before deactivating it.

We reactivated that account because we decided to go back to Zendesk, but only 333 tickets are in there. This is very scary because we were told our data would remain for 90 days, and it had only been 45 days since we deactivated.

We need to get back all of the 5000+ tickets. If the Zendesk team can somehow give us access to that data (it should be there because it's been less than 90 days since we deactivated), that would be ideal.

If they can't give us access to that data, we need to figure out how to import the entire content of each of the 5000+ tickets. That would include all user info, plus the entire ticket thread/conversation.

The CSV export we have does not include any of the threads/conversations, so it appears that the CSV import won't work.

How can we restore all the tickets with all of their contents included? Will the XML or JSON work? And if so, how do we do that?