Vodacom adding extra fees on contract without consent or notice

I app**** online for a contract on a specific deal. There was a deal listed under "Online Exlusive deals" on Smart plan for R179pm plus R6.99 for contract cover giving a total of R185,99pm x24. There was a similar offer available on the website but for 36 month contract. My quote no was VODACOMONLIN-***. I received an email on 11 December 2020 at 21H15 confirming the deal and the payable amount of R185,99 was confirmed. At 21H18 on the same date I received an sms confirming that it has been approved. On 14/12/2020 I received a sms advising that the order has been processed and handed over to the courier. On 17/12/2020 the couriers delivered the handset. This afternoon I logged into MyVodacom and with a great shock I saw that you are now charging me an extra fee of R920 for the handset which was never mentioned in the original deal on the website . The deal that was offered on your website was R179pm plus R6.99 for cover protection. There was NOTHING mentioned of any extra R920 fee for handset. I have screenshots of the deal and of the email send by you confirming the amount of R185.99 as the full amount payable per month. I will not pay for the extra R920 pm because it was NOT part of the deal offered and if it was I would have never app**** for the deal. I have contacted VC on Facebook messenger and tried to resolve this problem with no luck. All they say it that they will send me a new quote for the higher amount that will be applicable. It seems like they don't care about the original deal that was available on the website and the quote that was send to me and approved. How can VC just change deals when it suits them after delivery was made? I have already started using the device and accessories that came with the deal. I request that a Senior supervisor urgently handle this query of mine. Kind regards