Disgusting service on ***** case - R10,000!!!

On around about the 20th March I picked up very unusual data usage on one of my data contracts (number ***) . I reported this to the Call Centre and was advised there had been a ********** upgrade on this number. The sim card was blocked and I was told there would be an investigation into this matter and the data usage - approximately R10,000 of data in a three month period! I did not hear back from Vodacom so on the 24th March I spoke to Warner de lilly and again recorded a dispute of this data usage. I still did not hear back from Vodacom so again followed up by email to customer service last week and again no response. I called on Monday 20th April to follow up again and was told the supervisers would get involved and I would have a response by Tuesday 21st April. AGAIN, NO RESPONSE! So today, on the 22nd April I called again and spoke to Tsholo Phele (***). Once again I was promised a response - this time by 13h00 today - and surprisingly I have STILL NOT HAD A RESPONSE!!! I am furious! I am a good customer (with 5 accounts) and this is the service I get? I demand this matter is investigated and I am refunded immediately!!!