CANCEL....IS THAT SO HARD

Again so disappointed in DSTV. I called middle December to cancel my account on the 2nd of January. Which was not done. I had to wait to get to work to phone DSTV Call Center to correct the matter and i asked very nicely to please let me know why it was not cancel? and if i would be charges for a call center agents mistake, i was advised that they will call me back should any fee be charge and i did not get one call! not one! My bank then notified my that a d/o was taken for DSTV, but i did not have funds as i was not prepared for the amount! Yet again my bank charges are more than the d/o it self as i was charge for an unpaid fee! Why did no one call me back? why was i not advise on the outcome of my dispute? And why was i charged for a call center agents mistake?!