What is the difference in freeze vs attach a bank account? Under what conditions can this be done? Is there any fore warning when this is to be done? What are the ways to get around this saga?

An attachment is when the creditor seizes the account. A freeze is when account can't be touched by the account holder. A freeze may be instituted to prevent the owner from closing the account prior to an attachment.

In both cases a court order is required. An attachment can only occur after a judgement has been handed down.

To get around it, pay the bill.