Would I able to get the VOA in SANYA without all the 'emergency' or 'business' reasons?

I wasn't planned to join the trip but would like to suprise my dad on his 65th birthday as a family trip. They are travelling from Thailand and I will be travelling from UK. I found it too difficult to get the VISA done within a week time as in here we need to make appointment. The family trip destination is in Beijing, therefore I was hoping to travel myself to SANYA for few days sightseeing before meeting them in Beijing.

Please advise. Thanks.