5 Months down the Line and still being Billed

i finished and cancelled my contract in November 2014 with this Pathetic serviced based Telecommunications subscriber ! December i got billed , i contacted them and they said sorry , they had an I.T error it did not go off , i thought ok mistake . Now EVERY BLADY MONTH AFTER THAT IM BEING BILLED STILL ***!!!! . Now every time you must sit on the phone waiting to get through , i am actually writting this while i wait for the next available consultant!!!! been 40mins so far . The next step is going to the Police station and laying a charge of theft against this Pathetic Company !!! it seems that poor service is just becoming the norm here in South Africa!!!