How can you refuse to pay? It's part of the bill, isn't it? In most restaurants I've been so far at least. Also foreigner, so maybe I am missing something.
You can say you don’t want to or state some other total you’re going to pay that’s >= to the rest of the bill. Obviously that’s awkward and that’s why they make it the default, but you can pay less/no service charge/tip if you want to.