MTN South Africa

Hello

I have a sim contract with MTN , which I had since 2020 , I was called in 2023 and congratulated that I pay my bill on time and they are now going to upgrade my current plan to a new one, the new plan will be an upgrade on my current contract sim and I will receive a router for free , I received the router but my plan was not upgraded and I still paid the old amount until I received my monthly statements saying that I have a new contract with them they did a new contract for me which they never told me about now I am told to pay a cancellation fee on R1900 for a contract I never agreed with , MTN is not willing to help me but keeps on piling up my bill