This article will tell you how to undo an accidental merge of accounts.
Instructions
Navigate to Functions > Undo Merge
Manage filters, if needed
Search: Search for the users
Items per Page: Choose 50, 100, 500, or 1000
Note:
Results will auto-populate, so there is no need to refresh the page.
Select the Undo tool next to the merge action
Select OK to Are you sure you want to undo this merge? pop-up