Massive account for a data card

Good day, please can you assist me as a matter of urgency. On 2 July 2015 I did an application to put my pay as you go number *** on a data contract with autopage a consultant assisted me. I specifically asked for a 2GB data contract and on which she said yes I will pay R109,95 per month and I specifically asked for the top up contract as I am a single mother and are not financially in the position to be able to pay ridiculously high accounts. On 9 July 2015 I visited the Brooklyn branch and AJ assisted me and said that indeed it's an open account and he help me and still did a migration for me which is all good. On 17 July 2015 to my shock I had to do a my account check and see that there is an account of more than R 4000. to be paid which is unacceptable as before the application was done I had plus minus a 1GB on the card and then with the new one there should have been 3 GB more or less. It shows as unbilled calls and still if you check the statement you can see that the card was only used for internet as it is permanently in the Wi-Fi unit??? I know all calls are recorded and please would appreciate it if you can help as I am not going to pay this account.