Disappointed by how Vodacom has just been sitting on their hands when their consultant messed up my so-called upgrade

It pains me to have to write this but I am so frustrated Vodacom keeps sending me from pillar to post, promising me they've escalated the matter and will give me a call back but no one ever calls me back. It's gotten to a point where when I call in, I hear "This number has been blocked by Vodacom because of the high volume of calls..." Well guess what? I WOULDN'T CALL YOU IF YOU ACTUALLY SOLVED MY PROBLEM INSTEAD OF MAKING EMPTY PROMISES. I called in on the 28th February to cancel/do an upgrade. I was initially on a 10GB data plan and I wanted to stay on it but also add an accessory, the agent I spoke to advised me I would need to take a device if I wanted the accessory because it can't be added to a data-only plan. Long story short, we finalized everything (with the 10GB data I wanted and a discount promised because I have had this number for almost 6 years now). To my surprise, come the 1st April I got 650MB loaded on my SIM and not the 10GB I asked for. I don't know how 650MB per month even makes sense for someone my age but that is what Vodacom gave me. I've been calling pretty much every week of April and all they ever do is tell me that they have escalated the matter and that someone will call me with feedback. Last week I got tired of that response, the lady I spoke to told me she sent an email but I also wanted proof on my side so I DM'd Vodacom, even sent them the call date AND the time stamp to make it easier for them but still, no one has bothered. Tomorrow is the 1st, I'm in the prime of my youth but guess what? I will be getting a lousy 650MB to use FOR THE MONTH at the price I was quoted on the 28th February which included 10GB NOT 650MB.