I had the same problem before and I sent out several messages to the staff but got no response from them. They don't want to take any chances of having a lawsuit filed against them. So I just gave up on the idea.
My horse always shows up after I fast travel somewhere. It's annoying when they run off after a battle though. Instead of searching around for it I usually just shrug it off or fast travel to the closet location and it'll pop up behind me.