Data Billing incorrect

I've had this contract and phone from vodacom for almost 2 years now, one morning in August 2015 I got sms after sms that my data is almost at its limit, within 5 minutes my data was gone, more than 1.5GB. what is strange about this is that I was in my house where I have Wifi all the time. That being said I did log a call at vodacom and received a reference. September month the same thing happened. I haven't used up my mobile data in almost 2 years, why now all of a sudden?<br> <br> I phoned vodacom in October to find out what happened with the investigation, they just said that they couldn't find anything wrong.<br> <br> I know I didn't use that much of mobile data, I've got wifi at work and home!<br> <br> To get my number un-suspended I am willing to pay for the extra data, but only in bundle rates.<br> I did phone vodacom to find out if I can pay the extra used data @ in bundle rates and the person told me that their supervisor will investigate and let me know.<br> <br> I've been waiting for more than a week for any news from them.<br> I have always been a loyal customer to vodacom and I am greatly dissapointed in the manner this situation has been handled.<br>