Safe Financials keeps a log of Transactions within the system, even those that are deleted.
To find transactions that have been deleted:
Click appropriate Ledger (Purchase or Sales).
Select either Suppliers or Customers as per the Ledger you are searching in.
In the top half, among the list of Accounts, right-click and select Transaction Search.
Click Deletion Log.
It is recommended to use the Filter to narrow down the results to find the required transaction.
Note: This list however, is just a Log and transactions within the list cannot be recovered or interacted with.