DEDUCTIONS AFTER CONTRACTED HAD ENDED

Virgin Active Mitchells Plain. I signed a contract for 12 months. My contract ended 31/7/2020. In September a cancellation fee of R203.00 was debited to my account. Why is there a cancellation fee when I did not cancel before the 12 months. My contract ran its full term and had already ended 31/7/2020. When I called to query, they said the contract carries on after the 12 months and if you do not cancel, then you will be debited. Cancel what? There is nothing to cancel, the term is over. Question then, why when you join, is there a start and end date. This is then actually an indefinite contract!! Also how can Virgin Active just assume that you will have money beyond the period for which you signed.