Mr. Jones, I'm a little confused by you, now are you mean that first you will go to New Zealand via London and Shanghai, then in January, you will return to London from Auckland and transit Shanghai again? You will transit Shanghai for two times, right?

Now you are in Switzerland, so you can apply for Transit visa in Chinese embassy in Berne or Chinese Consulate in Zurich according to the consular districts. You can download the application form from https://www.travelchinaguide.com/embassy/visa.htm