This exact thing happened to me the other day as well - twice. I assumed I wasn't paying attention properly the first time, but the second time I figured something was up.
I had my cursor scaling turned up to 125% at the time, and I noticed when clicking on map marker toggles it would sometimes click two instead of one. I haven't had it happen since I turned the cursor scaling back to 100%, but I generally keep just the thing I want to sell there just in case.
And no you don't get any trading fees back by design. You pay 5% to post something for sale and don't get anything back if you remove the listing, and another 5% when it sells.