carnival cruise lines first class cruisers offered a $1200 cruise by phone for $500 plus port fees of $149. withdrew cash immediately from my accout, boca raton, Florida

Carnival Cruise lines did not offer you this cruise.  First Class Vacations of Boca Raton did.  Your beef is with them, NOT the cruiseline.

This complaint lacks a lot of details, but am I to understand some 3rd party travel agency called you out of the blue and you just gave them your account info right then and there?  And worse, you gave them yourt debit info?  Before giving them your money, did you check Carnival's prices to see what their advertised rates were?  A travel agency discounting a $1200 cruise down to $500 is not only impossible these days, it goes against the cruise lines' policies for TAs. 

Unfortunately, I think you are screwed.  If I misunderstood and you used your CC instead of debit, I would file a claim.  Otherwise, cruises are non refundable after a certain date unless you have the proper insurance.  That said, they do have to refund taxes by law. 

As far as I know Carnival Cruise Line only does cold calls to people who have taken a cruise with them before. If you don't want to go on another you just tell them no thank you and that is it. There are NO high pressure sales calls from Carnival.

When did you pay for the cruise and when were you supposed to go? If this was a last minute cancellation then what does the contract you were sent along with your tickets state the refund policy is?

Did you take the trip insurance as well? Maybe check out that option to.

My gut tells me this story is at least 90 to 95 percent made up but please prove me wrong by providing a time line.

Also, You must have given them the account info for your credit card unless you provided them a checking account to take it from. You always have the option to pay in installments (depending of course when you were planning to take the cruise).