Theft from my cell by Victorious Technologies

I went to MTN when I found that money was being deducted from my account only to find that it is Victorious Technologies. They are taking money from accounts without any authorization. I asked MTN what action I can take against these people and I was told that these companies can detect that you have a contract and airtime and start deducting without any authorization and that nothing can e done to block them doing this. I find this hard to believe as most things can be blocked or is MTN involved in these ****s. It is disgraceful that this can happen to unsuspecting subscribers and that no-one can help.