Extremely High Account

I received an account from Vodacom for the month of January 2015 and my data usage amount that was invoiced amounted to R 12 120.26??? I do not update apps or use the internet very often, if i used the internet 3 times (between 5 and 10 minutes a time) it was a lot. I immediately went to my bank and stopped the debit order as i first wanted clarity on what was going on with my account. I visited the Vodashop at the Middelburg Mall, Mpumalanga where the staff were very helpful. I logged a dispute on my account and was told that Vodacom would sms me a ref number, I could only then carry on with the dispute. I called Vodacom again once I received the sms and was promptly told that due to me stopping my debit order my phone would be soft locked and due to month end, the investigation will take some time. I went back to Vodashop today and one of the consultants checked my phone's history, the data usage that showed in my history only amounted to R 4000.00?? Vodacom accounts dept told me today that no dispute has been logged? I have reinstated the debit order, but my phone is still soft locked. The accounts dept says there is no lock on my account?? Unacceptable!!!!