Upgrade confusion

My Vodacom contract is due for an early upgrade on 17 Dec 2017 - 3 months before contract expiry. As I likely will be unable to process the upgrade at that time I requested from the upgrades dept whether I could upgrade now - effectively 4 months early. The upgrades call-centre said they could facilitate this.

I was hoping to utilise either the Black Friday or Summer deals that Vodacom advertises on its website but was told that the upgrade had to be done via the call-centre and the devices offered are much older devices that I am not interested in. They also said that they cannot authorise an early upgrade and pass that onto the Vodacom online dept which offers these Black Friday and Summer promotions?

Is there no way to process an early upgrade and take advantage of the upgrade specials the Vodacom website offers? I've been a Vodacom customer for many, many years and would really appreciate some assistance in sorting this out please?