Vodacom 'Upgrade', without device, prevention practices

I have had extreme difficulties in 'upgrading' my contract in terms of staying on a similar package but not taking a device. It is called a SIM-only contract for 24 months, but for some reason, this can not be done in a Vodacom shop. I have visited both Nicolway and Hyde Park Vodacom shops and encountered similar issues. Nicolway is always offline and promised me they would contact me and give me feedback on how I can 'upgrade' my contract. I never heard back from them. I have been out of contract since the end of March and have been paying R2319 for a Red VIP 22GB package. The hurdles to 'upgrade' a contract to a similar Red VIP, without a device, appear to be deliberate to prevent loss of revenue, no matter the cost and inconvenience to a customer of 28 years. Finally, a consultant at Vodacom Hyde Park heard and understood my frustration as she tried to 'upgrade' my contract to the Red VIP 50GB package at R1299 in-store. Once again this store was prevented from doing so, and it had to be done through the call centre ***. We could get through on my cell which has been the case for several weeks the consultant used her cell and we got through to 'upgrades' and after spending 20 minutes with security checks etc. trying to load the package the on-line consultant said they could do the 'upgrade'. It has go to retentions, option number 2 on ***. After more security questions, trying to find the package and then loading it another 30 minutes the person said they need to manager to authorise it. This is all on 31 July. The person could not find a manager but promised to get it done on the 31st of July and to call me. 1st of August, the person called, saying it could not be authorised and had to go to escalations. Escalations called to say they can authorise it, but as it was the 1st it will only be effective 1 September. Another month of being an additional R1020 for less data. It boggles the mind that Vodacom gets away with such blatant anti-competitive practices.