Still waiting on a reply

I’ve been trying to get hold of a iPhone 6S handset. After phoning around, I was informed that Vodacom Canal Walk has one 1 handset left. They want to offer me a deal of R599 p.m for the phone. This is way more than what the other networks are offering for the same deal (R350-R399). I’ve been a client of Vodacom for many years, surely they can offer me a better deal? R599 is just way too much, it’s almost the price of a iPhone 7 and the phone is 3 years old. I would appreciate it if Vodacom could take this into consideration and see what they can do for me?