Iceland Air Corporate Office Headquarters

Hello: I was trying to book one of Icelandair's Stopover flights on my way to Glasgow, from Chicago. My understanding was that there would not be any extra charge for the Stopover. But, a direct flight to Glasgow, from Chicago, is about $700 (mid July), while if I use the Stopover option (same date) it is about $1500. This doesn't seem like a good way to promote Stopovers???? Why is it twice the cost for a Stopover??
After some back and forth with some of your representatives, I gave them an exact example, since they were saying that the price differential could be explained away because of different flights, etc.: I was looking at flight FI852 (& FI 430) on July 12, 2017, from Chicago to Glasgow. Direct flight is listed (lowest fare) for $654. Same flight, with a Stopover is listed (again, lowest fare) for $1448.
Here is the response from one of your reps: "Please note that the prices for stopover are pending availability and if the same price is not available on the continuing flight, automatically the fare total fare goes up to the next class on the two flights." This answer contradicts what your advertisements say about no extra charge for Stopovers. Nothing is said about "pending availability". Even if not intentional, this looks like a classic bait and switch scheme. Why would anyone Stopover if the fare is then doubled? Not a good way to promote Stopovers. I am disappointed. I had looked forward to seeing Iceland.