Second time I ask you to stop harassing me

I complained before, asking Nedbank to stop calling me for outstanding debt as I am not a customer of theirs. Yesterday I got a call from their collections, I was shocked and told the woman I asked to be removed from their system as their client is not using my number since 2012. Today I get a missed call from the same number.

I have asked before and complained before. What is it going to take for you to remove my number from your system? I do not owe you money - your client is not using my cell number.