The price you were quoted is really good, so I did a quick search on Royal Shuttle. What I found was not very positive. There were MANY bad reviews on yelp, trip advisor and google.
The complaints ranged from not being picked up on time, to rude drivers to being charged 2 weeks PRIOR to their pickup, then getting additional fees added to their credit card after the fact. People also noted not being able to get refunds when they had to cancel.
Hopefully you did not pay for this upfront and if you decide to cancel can do so. There are a lot of transportation companies out there, many that people here have recommended, but with any of them, I suggest checking out reviews on yelp or trip advisor to get more opinions.
Good luck!
We have used
FL Tours (the trip from port to MCO was very good, we loved the driver, but the trip from MCO to Port was nothing that I would rave about. Second cruise we used Executive VIP and was not impressed. The town car was old and electric windows didn't work, driver smelled of smoke (and smoked while we made a stop at a liquor store so then the inside of the car smelled when she got in), just not professional.
Last cruise we used Spaceport Transport and loved them. Good rates ($93 cash each way), they used a mini van instead of a town car, which we preferred as we had more room for people and luggage (we are a family of 4). The driver was very courteous, professional and personable. We would definitely use them again.