Hello there,
It seems that you've got into a big problem. THE BEST THING TO DO IS TO ASK CUSTOMER SERVIC CENTER. But because I own the BigWorld Game Engine I can diagnose, NOT SOLVE your problem.
I can't say always, but in the most cases your problem is caused by some script bugs. There may be an incomplete download or anything else. Remember that I said in most cases, not always. Try to do a Check game by going Settings in upper right corner, support tab and there CHECK button. Confirm any questions.
I also recommend you to download through torrent. If you try to download not from torrent, may result in file misses. I tried to download World of Tanks without torrent and I noticed that the audioww with the audio files were missing.
Hope I helped.