Show appropriate error when order has free tickets(unverified user)

[mrsaicharan1]

Describe the bug
When an unverified user orders a free ticket, the server side works fine but the error message on FE is irrelevant.

To Reproduce
Steps to reproduce the behaviour:

1. Order a free ticket from any event with a new email(unauthenticated)
2. The order does not go through(expected) but error message should be appropriate

Expected behaviour
Should show up as unverified user cannot order free tickets