Agree that Carnival must refund current deposit and agree the SOL is implicated on any claim Carnival may have had against (if any) OP. That being said, Carnival is a private company and can ban you for any reason (that doesn't violate the law).
You're absolutely right - BUT - OP's beef is with the sleezy agent not Carnival. Carnival is out thousands of dollars and has every right not to accept passage in this circumstance. OP needs to deal with the travel agent, get the money, and pay Carnival - or use other cruise lines.
Nah - Carnival isn't to blame here. The sleezy travel agent is. Your beef is with him - not Carnival. Straighten it out with the travel agent - get your money back - and then repay Carnival.
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