Vodacom incompetency in sorting out there own systems issues

Vodacom has lost all my confidence in them resolving issues they created and will lose me as a client.

I have been a loyal Vodacom client for the last 15 years and I was a happy client but then they phoned me early last year 2018 saying I can upgrade. At first, I received SMS notification I can upgrade but I ignored them as it felt to early since my last upgrade. Then Vodacom phoned me and said I can upgrade I told them it feels to early and said they must make sure they had a look and said I am, and I should upgrade. My phone I had at that stage was an apple iPhone 7+ and I wanted to go back to Samsung, so I upgraded online to a Samsung Galaxy S8 in March 2018. After having the phone for 3 months I had a look at my invoice and saw I was still paying for my iPhone 7+ device as well as the Samsung S8. I phoned Vodacom and asked them why I was still paying for both handsets as I was told I could upgrade. I was then told it would only be for two months as my previous contract only expired then. I was not happy as I asked them to make sure my contract was finished but just decided to accept it. After 5 months I looked at my statement and saw I was still paying for two handsets yet again I phoned Vodacom and asked them why this is, they came up with a story that my contract I had on my iPhone 7+ still had 11 months on it and I said then why did they upgrade me after I asked them to make sure it was time. Vodacom only allows upgrades after 22 months of the 24 months contract duration. This process went on up until November 2018 (8 months) where they said they wrongly upgraded me because of faults they had on their systems they came and collected the Samsung S8, cancelled my upgrade and refunded me an amount that I could not confirm if it was correct because I was told I could not speak to the consultant handling this issue. December came and guess what I was still being charged for two handsets and this went on until the end of March 2019 another 4 months. My contact with the iPhone 7+ should have ended on the 31 March 2019 as confirmed by a Vodacom consultant in January 2019 but guess what I’m still paying for that handset. They have no clue of what is going on, on their systems and even if they try and sort it out they once again showed how *********** they are as a service provider sorting out the issues they create. Since this issue started that was created due to their systems being wrong I have been treated as it is my fault with most of my queries being closed on the app without anybody dealing with the issue or phoning me back. It has been 15 months since the upgrade and 11 months since I phoned them to fix this issue and it still has not been sorted, is this the dealings of a company that deals with their clients in a professional manner or that is competent enough to sort out their system issues without the client having to pay for a phone they don’t have or still paying for a phone after the contact has expired.