Taking money from my account

Web Africa have been deducting R699 from my account for the past 2 month for a line that was upgraded - The new line has been paid every time but they still deducting from my account for the old line. Phoning them is absolutely useless they just keep transferring you to someone else with the problem not being solved! this is absolutely pathetic!!! you are now taking money from me for something that i have upgraded and paying on a monthly basis! this line will now be cancelled.