MBD collections harassment

This company called MBD Collections. They have no people skills and they don't have any clue how to resolve a dispute. In 2019 i was legally sequestrated by the high court of South Africa. All my debt was listed and then went into my estate. I have since been rehabilitated. They are now saying i owe them R6k for an account from 2018 and to top it off they call me 2-3 times a week. I have sent them proof of all my documents but they just keep on harassing me when they realise they have spoken to me before they then drop the call they are rude and have no idea how to treat people its really disgusting.