Visa on Arrival from Hong Kong to Shenzhen

I am currently in Shenzhen on a single- entry tourist L type and would like to visit Hongkong for 2 days. My flight back home goes from Shenzhen so I would have to enter Mainland China again for one day. Will I be able to get a VOA to return to Shenzhen to catch my flight home? I am an Italian citizen.
Thanks for your help!