Can I get a 72 hours transfer visa if I have a ticket to and from Hong kong?

Hi Christina! Do you mean to get the 72 hour free transit by flying from Hong Kong to mainland and then back to Hong Kong? If so, I'm afraid you cannot make use of this policy because the itinerary is not considered as a valid transit.

It is required that only those who have HK residence permit can apply for the mainland entry permit from there, so I wonder whether you can do it there. Anyway, if you can, it takes four business days to do it.