Gayle - I haven't heard of these apartments. I've just searched the holiday review sites and a general search - the only thing that comes up is the Grand prestige
Hotel in
marmaris - and Grand prestige apartments in Dalyan.
ICR staff may know of the hotel - it could be it's a name change this year.
If you don't find anything I'd get back onto the tour operator and ask for some information. I'd ask for the phone number of the hotel and call them to check location etc.