Outrageous data account with no feedback on query

I have had numerous communications, both on email and telephonic, with Vodacom to sort out an account of R884.01 outstanding, when in fact Vodacom is owing me R6 after ending my R99 2Gb data contract which expired last year (2015). I carried on on a monthly basis after the contract expired.<br> <br> My first query was on 23 February, which opened an audit when I realized my account is going up in Rands for data (That time was over R897), when my data, where I had 1.78 Gb left, was not going down. The reference for the call was S3-GNN1E-E1BUP. It was said I will get feedback in 7 -14 working days. Never received feedback - only received a bill of R884,01 on 10 March, and a notification to pay on 9 April.<br> <br> I once again contacted Vodacom telephonically, where I was between 3 departments (legal, accounts and customer care), having to explain the situation every time, and no one could assist, in fact the phone was put down because they couldn't hear the reference number I tried to read to them. I reverted to email, and on 11 April it is said I would receive feedback in 48 hours for reference S3-GSV6Z-ZK43 (no feedback - no surprise).<br> <br> What more must I do to sort out this ridiculous situation??