Abnormal Billing & Lack of Access to Information

I have a company cellphone which has got a limited amount that I can utilise. I started with the company in April 2013 the Blackberry Z10 cellphone and have always used this number. From that time my cellphone bill has been fine and less than R1000, but in October 2014 I was informed that my cellphone bill for August 2014 was about R32k for data only which seemed abnormal to me as I had not done anything differently during this particular month. I then queried with the company via the employer to do a thorough investigation, they said if I consent they will only give me a report verbally as they are legally not allowed to give an investigation report in writing, I'm not happy with this as I cannot take my time and apply my mind on the verbal report. I opened a case with SAPS as I believed that there is a serious mistake or someone had used my credentials to access my account, and SAPS will require a written report. I thought that I have the right of access to information and the report will be the only way of getting facts and satisfy myself that Im responsible for the bill. I would really appreciate assistance and clarity on this matter, in order for me to move forward with thi