If your stuck in HK and can't get another visa, you might try a team visa.

It's good for 30 days.

What a team visa is, you have to get someone else who is also, stuck there or needs a visa as well and go in together but you must leave together after this team visa has expired. I used it once, it worked out fine for me and a friend.

It doesn't matter how many are in this type of visa.

I have 2 contacts in China, that might be able to help you with this, it's worth a try.