If you want a cheap flight from Norwich to Shanghai, you've got two airlines to choose from.
Shanghai Pu Dong Airport is just one of the airports in Shanghai. If you're not set on a specific airport, try changing your search from Shanghai Pu Dong Airport to Shanghai to see a broader range of flights – they might be cheaper. It usually takes about 15 hrs 45 mins to fly 9070 km to Shanghai Pu Dong Airport.
There are about ten flights to or via Shanghai every week, so you have plenty of options.
If you're planning on going to Shanghai during this time, you could take a look at other airport options. Or you could try to get a last-minute bargain.