Limitations with Blizzard Support for Activision titles.
In regards to Activision, we only handle the distribution of the game client for Activision. We will assist with anything related to the desktop application and anything with the game client that involves purchasing, activating, downloading/installing and launching. Anything that occurs after you can press the play button is going to be addressed through the Activision support portal: Support Options | Activision Support
Definitely try Chestnuts solution of updating your system, including bios, network drivers, gpu and audio. Most games that update frequently need all the latest updates to run properly so keeping those up to date will be the first step here.
Beyond that disabling potential software that could be eating resources or conflicting with the game may help. Beyond that, reach out to Activision support via the link above.