Well, they could stop drinking them since they don't have any nutritional value in the first place. My mother rarely bought soda when we were kids, and she sure as Hell didn't let us drink it at meals. Milk or water only; soda was a dessert if we had it at all.
Most restaurants here--chain ones, at least--do free refills but I the pubs/bars I've been to charge for refills, as well. I haven't noticed a particular price jump recently but I don't buy much soda so maybe it escaped me. RC was still between $1 and $1.20 a 2-liter a week ago when I got some to make the cola-chocolate cake for my brother.
But, yeah--soda companies and bars could give soft drinkers a break. The dude at our table at the Battlefield Band show last night drank quite a bit. He probably would have, anyway, but I was still glad his wife was driving them home.