WRONG STATEMENTS AND STILL DEDUCTING

I went and cancelled my telkom line at festival mall the 21st of march so they said it will take 30 days to cancel (no problem i thought). I got a statement for april FOR R1099? and I am only paying for voice line i am using afrihost as my ISP and pay them dsl line rental? I went and enquired about the statement, according to them i made phone calls on the line ( I dont have a phone connected on my line only use dsl for internet obviously) they cant give me statements or numbers that have been dialed and my line still havent been cancelled this was the 13th of april about. Lady told me that the line is being cancelled middle may because the cancellation application(that was done on 21st of may) only went throught the 12th of april. and surely they billed me another month with R900 for april!! and im only suppose to pay voice line rental!. I called them and they logged a case that i am owing R1965! and they will try and resolve the case this morning they debited R1000 from my account and guess what... my line is still active and still they continue to bill me the wrong amount!