I want the policy cancelled

I took up service plan with 1st for women now plan has lapsed they say they will continue debiting though they wont pay for my next service.My car was serviced twice with them and they debiting and amount of R543 and have and amount that add up to R7000-+. Now i want them to stop the debit order as my car wont be claiming from them They say i must pay R7100 to settle the outstanding Which outstanding as this was not a loan ,and if it was clarified from the word go that i will pay them even if service plan lapsed i wouldnt have taken this service plan. This is only brought up now . I want their debit to be stopped so that i can save up for the next service for my car.