We had friends staying there a few years ago. We used to pick them up and bring them over to Calis for the evening, then they did a deal with a local taxi driver to do the round trip.
If your family ask the dolmus driver to drop them at the sign for Calis Beach at the top of Baris Manco Boulevard by the big Citroen Garage, they can walk down to Caiis, but better still just catch the dolmus down to the town centre.