Been charged for device never had

I was informed on the 22 April 2015 by Bethlehem Vodacom that I had been charged for a tablet on cell number *** which was sent back to Midrand on the 13/06/2013. I called the 082111 number to log a query so I can be refunded. On the 24th April 2015 I faxed all the documents to *** and again twice on the 28th April 2015, I received an sms confirming that documents were received and I would get feedback within 24 hours and with ref nr S3-82G7S-SIVY. I never received any feedback within the promised 24 hours. I have been calling every week since and had spoken to Palisa, Makhadzi, Mazibuko (twice), Nosipwo, Lee-Anne (supervisor who promised to call back, never did), Sibusiso and Sandra with the same answer, they are still looking into my query. Sandra called back on 23rd June 2015 to find out if Riona (person dealing with my query) had called me with feedback, which she did not. I was told once before and last night when I phone again that the query had been closed, with no feedback or phone call to me informing me what the outcome is regarding my query. Lee-anne, the supervisor also said that a Brian person was dealing with the query would call be, but he never did.