It doesn't matter what stones wants. He has a contract. Look at Suarez, lewandowski, etc. you have to stay if they refuse to sell. He might not be happy but he will only ruin his career and he's not stupid enough to do that. He can go in the summer and by then will be worth even more and have bigger clubs than Chelsea looking for him.
Both those players and many more were professionals and kept playing well because they are a pro, and because they knew they were playing for a contract.