I got taxed on my DSLR in China

Hi,
I recently bought a 60D on Hong Kong an decided to take it across the china border into Shenzhen at Lowu station. The customs officers told me I had to pay 700 RMB in order to bring it into china. Why!?! I told them it is for my own personal use etc but because they said it was new I had to pay the tax. I don't understand because I don't intend to sell it - I'm a tourist so I'm gonna need to bring a camera to take pictures etc.
Anyone else had this problem?