We have had only positive things to say about Disney excursions, but, I know going in they are more expensive and I make sure they are the RIGHT ones.
EX. I would never do the dog sled in Alaska through Disney again WAY too expensive. But, VERY glad we did the Butchart Gardens through Disney, we were 1 1/2 hours late and if we did this on our own we would have been left behind.
Just make sure you have time to get back to the ship early if you do things on your own.
From what you say I doubt very much Disney will refund your money. Sorry.