Sadly I've cancelled my cruise

I was due to sail Eurodam 25th Oct 08 out of Fort Lauderdale. The cruise has now been booked by a group called aquafest. As we have our young son travelling with us I feel it is inappropriate. I have asked my T/A to change me to another cruise, as our flights are fixed and paid for. This has come as a great shock, as our agent didn't tell us about the group booking, either before, or since we booked. I hope we can either change cruises or receive our deposit back. Any advice would be welcomed. Regards Mark UK No Longer Sailing Crying or Very sad