Vodacom *****ing airtime and data

I have a Vodacom 3g ****le which was on contract for R109 per month for the last few years. Last year July when I visited Vodacom in Woodmead to query the number which is on my dad's name, I was told that since the contact was never renewed and we did not take out a new device, that we were being billed on a month to month basis now and the number and ****le could be cancelled at any time. The number for the ****le is ********** 945 Then we realised that in 2018 Vodacom started billing us 10 times as much monthly. R1307.34 in Jan. In Feb the device was not working at all but we got billed R298. Consultant at Vodacom in Mall of Africa said the system says all is ok. We then got billed R3856.15 in march. In April we went to Vodacom Head Office in Midrand after being billed R2148.56 for April. I took the device with me and the sim card was inside it. While we were talking to the consultant with the device in front of me, the consultant Wanda confirmed that the system was showing usage for the same day and was increasing. How is that even possible with the device and sim in my hand???? They also told us that the device is on a new contract since Jan 2018 but could not say when the contract would be ending. We at no point signed up for a new contract. Hence there is no paperwork for it at all. He then proceeded to convert the number to a prepaid number. He then sent the case off for an audit and that they would contact me within 7 days via email. The reference number given to me was wanda1548 Until today I have not received any email or call or any results of their audit. My dad is now being asked to pay a final sum of R2326.57 which is very unfair after we already paid them for the previous months. This is terrible service from Vodacom and not very customer focused at all. My own phone number also loses airtime by itself even if I switch mobile data off and make no calls or sms's. Vodacom need to fix their systems, policies and give proper service to their customers and stop *****ing from them! Very unhappy customer and I will definately not be renewing my current cell phone contract with vodacom once it expires. Another provider will do better.