Telkom refusing to correct my billing even though they’ve noted the error

I’ve called Telkom weekly for the past 3 months. They’re incorrectly debiting my account and with each call they’ve advised that they have updated the amounts yet it still hasn’t updated !? This is the 4th month ! I need a refund ! Can someone assist me with ombudsman contact for cellular networks please I’m so frustrated with Telkom and they never have a manager available to assist