I was denied boarding at airport in france.

I had planned to arrive in shanghai on the 4th October at 0700 and stay for 2 nights at a hotel then leave to go to the port at shanghai ( baoshan )and departed at 1700 on the 7th October to go on a cruise.My ship had a day at see then arrived in Japan then Hong Kong, Vietnam my final destination was Singapore where I had a flight booked to return to France.I had checked other Internet sites and was certain we could use the 144 visa free transit.I contacted the immigration also.The airline said that the port was not a form of departure from China and my mother and I where denied boarding, we returned home and missed our long awaited holiday.Can anyone confirm if we met the requirements as we had all our documents and feel that the airline was not helpful.Thank you in advance Samantha from the UK