This kind of thing happens frequently, unfortunately. If the class of service is your major criteria, you're better off spending the night and flying in the seat you want the next day. This is a solution not good for most travellers, but when delays happen, the airline's goal is to get you from point A to point B and they're not concerned about where you sit. It's all part of travelling by air these days ... not that long ago, an airline would go to great lengths to accommodate you, including booking you on a different airline. But today there's little help unless you're at the top of the elite program.