Overbilling- Unfair Credit Practices

I have been a loyal vodacom customer for years and have multiple contract lines. In June 2017 Vodacom processed 3 unauthorized debit orders against my bank account and upon inquiring I was told this was a system error and I should reverse transactions with my bank. I reversed the transactions as advised, in July 2017 my statement had R300 charged for unsuccessful debit orders which was paid. After numerous calls to the customer care contact centre requesting a credit note on my statement, nothing was done. I then decided to pay R300 less than the statement amount in August 2017. I have since been receiving numerous calls stating my account is in arrears for the past 3 months and have made several calls to the customer care contact centre with no assistance. Yesterday my lines were blocked because my 'account is arrears'. After several service requests and escalations in the past 3 months, still no assistance. Now I'm told I must pay to unblock my lines. This is bad service and unfair credit practices. I DO NOT OWE YOU ANY MONEY! YOU BILLING AND ACCOUNTS PROCESSING IS UNFAIR AND DISADVANTAGES CLIENTS! YOU THEN UPDATE CLIENT ITC RECORDS WITH THIS INFORMATION, IT IS ********* WHAT YOU ARE DOING!