Outrageous upgrade prices vs advertised prices

I was due for an upgrade end of August 2022. I looked online for an upgrade and the only deals that was available for the phones i wanted was 2x times the advertised price and I'm not eligible for the advertised deal. I called to the call centre to find out why and i was told that I am only eligible for cash deals and not month to month deals and i must pay in R15000 and pay 2400 per month for 36 months, what a joke. I have been a loyal customer with Vodacom for close to 5 years, I have religiously paid my contract on time and have never received a call for late payment. Now that i want to upgrade i must be ********** for being a loyal customer and be told things that dont make sense. Times are hard already, i don't need to be paying more than what i budgeted for a cell phone as if i am paying for a car. This week I am parting ways with Vodacom and people need to know what you guys do to loyal customers.