Track and Recover stolen phone

Hi

I wonder if somebody can assist. My bro was a victim of pick pocketting at the Kanye West concert in JHB this past weekend. His Samsung Galaxy S2 was taken. He was able to track the device to somewhere in Springs but we haven't been able to track it since.

AVG was installed on the phone which alerted my bro that the SIM card was changed with another Vodacom SIM and emailed the Serial Number of the new sim to him.

Is there any way we can track and recover the phone with the SIM Serial Number and IMEI details??

Any help would be appreciated.