144 HR visa mentioned on Chinese Embassy site

Hi,
I think we qualify for the 144hr twov been in contact with the Chinese Embassy in the UK and they say they have no information on this only the 72 hrs. We arriving in Shanghai from Hong Kong in 3rd Feb 2019 5.30am via the cruise port. We then from Shanghai airport to the UK via Dubai on the 6th February 2019 at 23.00. the cruise ship have said we can try when we get there but if we are concerned just to get entry permit. This works out costly if the visa exception does exist and we qualify for it. Can you advise please. Thanks in advance.