Saya Recoveries harassing me!

Saya recoveries phone me twice per week, this has now been going on for more than a year. Every time I tell them the same story, and they just keep on phoning me in connection with my Eskom account. Eskom transferred the deposit out of my account without my consent. I keep on sending the proof to Saya, but they just keep on phoning me. How can I stop this? The lady that phoned me today at 13h25, is extremely arrogant, and very confrontational. I would love to report her to her seniors, but it is impossible to speak to them. This is the 4th recovery company that has phoned me about this. It just doesn't stop!!!