Cancelation

I bought a rent to own car from gemini motors last year 24 August... So as I went to the dealer I got a surprise the installment is R8800 so I agree the sales men told me it's for 6 months after the 6 months then I become a golden client... And after the 6 months the installment is going down to 3500....last month I call him he told me they know longer working with planet42... So I can planet42 to cancel the contract due to the high payment so I ask them for a less payment and they said R6811 which is still to high for me so I cancel everything now I must pay a cancelation fee of R8800... The car is still in a good condition but to me I can't pay that amount anymore cause it's alot of money...