Diana with Philippines passport,Arriving from Japan Caribbean Cruise at Shanghai Port .

Diana with Philippines passport,Arriving from Japan Caribbean Cruise at Shanghai Port then booked flight to Hong Kong the same day less than 12Hrs upon arrival stay in Shanghai airport for my flight to Hong Kong,I plan to go to visit Shenzhen for 3 nights and there after fly back to Philippines thru Hong Kong.(Since I was only given double entry,in which I will use in Shanghai from Philippines to board the Caribbean Cruise in Shanghai.)How can I enter Shenzhen China if the immigration will get my other China visa at Shanghai,is there be a way?