disconnects during zombie games!!!!!

If you're disconnecting, but no one else seems to be (based on the lack of people having the same issue as you) then my first assumption is that your connection to their servers is poor, and dropping out.

• Check your NAT settings. (It's a long shot, but worth it, if it fixes the problem)
• Check other games you have that have multiplayer online and see if those are suffering from any type of lag or disconnects. That will narrow the problem down to this game
• Try playing a Garden Ops round where you are host. If you find yourself DC'd, then it has to do with the li between your servers and EA's. If instead you notice a ton of other players dropping in and out, there's a good chance that it's YOUR router or internet connection that's causing major problems, resulting in your troubles.

Also, I want to point out that throwing a fit by demanding a refund on a game because they haven't managed to help you yet is innapropriate, and childish.