Downgraded my account without my conscent

I received a call from a lady from Vodacom towards the end of November, she indicated that I will be receiving discount on my instalment but will still be receiving the same airtime. The lady said I will receive R150.00 airtime and will only be paying R119.00 per month, I asked numerous times if the was a catch to this and she said there's none I'm due to receive a discount on my current contract. I then received a parcel from RAM Couriers which I sent back to Vodacom immediately as I did not order a device. Vodacom called to say I must accept the parcel from RAM as its not a device its just documentation explaining my contract terms, I received a Microsoft. on 01 January 2018 I was shocked as I only received R98.00 airtime and a debit order of R213.80 went through, I called Vodacom on 02 January 2018 to query this, I was informed that I opted for a downgrade and I have been charged a fee of R150.00. I asked Vodacom to reverse this and refund me R150.00 as I was not informed of all of this and I did not even opt for a downgrade, they gave me a reference number which they keep closing with inappropriate feedback to my query, ref number is 1- ********** ********** , I am also receiving smses that I'm on flexi u chat 110, of which I request my account to be kept as it is as R150.00 Monthly airtime and I'm paying R158.00 for it including the device. I need this resolved as there is no way I'm paying a fee of R150 for something I know nothing about, I did not request a downgrade, my account should be kept as it is, I'm so frustrated with the level of incompetency and cheating.