BMW 116i 2013 Problems

Your car is out of warranty, so you would have to make a goodwill claim for BMW to replace the bottle free of charge. I think they should come to the party with the cost of replacing the bottle, and by all means try that, but I doubt you will be successful. There are many plastic components used in the cooling system on BMWs, and like the expansion bottle on your car they all eventually give trouble. In my view it's poor engineering.