Here is a list of taxi companies that operate in Dinard and the airport. This is not endorsement of any of the companies listed below. Just for your information. If you know of another company or have had a bad experience with one listed below please tell me.
If you need to book a taxi or are looking for a price I suggest you email either or both of the companies above. They should be able to understand English and reply to your request. It's also a good idea to book in advance so you don't waste your time waiting for a taxi to arrive.