Contact Cancelation

I visited Mtn branch at Vincent Park in East London on the 31/01/2024 to get myself a month to month data simcard deal since I like them because I can cancel it anytime I need, So I was convinced by the sales agent by the name Bongiwe to get myself the 200gb that comes with a pocket router then I asked her but it shows that it's 24 months contract that you asking me to choose, then she said to me l can even cancel this deal anytime I want since it's a data simcard, now today it's 29/02/2023 I went to them to cancel the contract cause I'm no longer interested then they said I must phone the Head Office for cancelation of the contract and the Head Office said I must pay a cancelation fee of about R1000, then I said no ways I was never told there would be a fee when I need to cancel this contract and Bongiwe who made me to choose this deal admits that it's her fault and I don't have R1000 to cancel this contract. I need help this too much for me