Loyal teacher hurt by Vodacom during Covid

I was told on my last upgrade that my contract would remain the same after 24months, however, I would not have a new phone unless I migrated or upgraded to a new contract. For the last 4 months I have been charged R1100 more as they say this is what the contract is valued at now. This is completely contrary to what I was sold on and asked them to retrieve the call, since all calls are recorded. I was told billing was correct. I made these queries in July. I am still trying to get a refund as this is contrary to what I was told and I was not informed of any changes. When I saw the debit order still go off this month I thought I had better upgrade before I lose my house or my car. I am living on a teacher’s salary so this is a possibility. I was told that the same contract is R600 less than what they have been charging me, and, they will appeal to get that reduced further. How can I be charged more than the actual contract price? When I asked if that would apply from this month I was told that it was too late, August had already started. I said that I had been trying to resolve the issue and the delay was no fault of mine. I was told there was nothing I could do and I would be charged for a fifth month an extra R1100. I still use my old phone. I have been with Vodacom for 22 years. Is it the loyal paying customers that take the hit during our darkest hour?