locking of bording cards

this is now the second time my card is block the first time I was asking why? apparently I go thru the turnstiles without swiping my card really! why is the turnstile open when I swipe and go thru shouldn't it not open? Yet my card was stopped. the first time I went to enquiry like I did now they came back and told me I owe them R29 which I am still waiting on how they have arrived at that amount if I have not swipe 3 time as I am travel from the Park to Hatfield? and I am using the bus please this is ridicules if you don't swipe the turnstile should not open!!.and please common sense prevail the train schedule has change but not the busses, every morning a empty bus goes to Brooklyn because the train is late then we have to wait another 15minutes really