So disappointed with Vodacom after being a client for 20 + Years !!!!!

I have been a very loyal client with vodacom for the last 20 odd years, It seems every the service is getting worse and worse!! On Monday evening I received a message that my Credit limit bar had been a activated ? I didn't realise I had a credit limit ? Every time my data runs out I use the FNB app to reload data to my phone, so my phone outgoing call bar was activated, I couldn't use my phone ? This morning I contacted vodacom for them to tell me I tried to cancel my contract on Friday and my outstanding balance was R17000.00 ? again this being news to me ! I have never tried to cancel my contract!! They said I went into the Hyde park branch on Friday morning at 9:53am and cancelled my contract and that I needed to return to the branch to resolve the issue! I drive to the branch for them to assure me that nothing like this had happened and that they were in fact offline at that time so this was impossible! I called and asked them to cancel my Credit limit bar as I never asked for it, which they did and I could use my phone once again! Within 20 minutes my phone was locked again for outgoing calls! After spending around 90 minutes with Melissa at Vodacom shop ( Who was as confused as i) she said the only way was to log a dispute! I phoned vodacom another 5 times to reconnect my phone, and they still say I owe them R17000.00 for cancelling my contract ? They then saID IT WAS A SYSTEM ERROR and all would be resolved they would unlock my account ( at my cost by the way). 30 minutes again my account has once again been locked due to reaching this imaginary credit limit ?I am so frustrated with this and the entire process! Was assured the credit limit issue would be cleared, and that they would remove the invoice for R17000.00 as I never actually asked for my account to be cancelled, yet here we sit with my hone locked once again! Vodacom you are such a disappointment!