Vodacom Upgrades: illogical and disloyal

I have been with Vodacom now for as long as I have had a phone contract which dates back to a good 12+ years. For my last contract term (April 2018 to now - it’s overdue) I have paid a total of R1100 to Vodacom for my iPhone 8 Plus and its insurance. I went to upgrade on Saturday for them to inform me that I have not been approved for finance for a phone that costs R879 a month (iPhone 11 pro) - less than what I pay now. Illogical, or what? I have never once missed a payment; I am not under debt review and I have a stable credit record of 658/705 - higher by a large mile than the national average (I used Experion which is who Vodacom use for their credit applications). I have now been through TWO portfolio reviews and have been been unsuccessful every time. I have called the upgrades department and been escalated to a supervisor but I have heard no feedback. I phoned back today to find out progress (as I promised to get a call back yesterday) and the consultant had no clue and could only send an email to the lady who had helped me - who I am STILL waiting for. I am now stuck with a phone that is slowly dying, needing to upgrade, but I am not having any luck. I have been approved at all other mobile companies for way more than I actually need but obviously would have liked to stay loyal - something that may not be able to happen now. If Vodacom continue this and do not solve my problem I have no choice but to cancel my contract and get help elsewhere. To add to this when I called today and selected # for phoning on the number I was querying, I was told I was not eligible for an upgrade but when I typed the number is manually, I was told (the truth) that I have been applicable since April. Does this not further show that perhaps something is wrong on their side???