Being HARASSED by Vodacom and their Associates

Shockingly bad service. Since I purchased my smartphone from their online years ago (2018 or 2019) the service has been bad. When they sold me a dual SIM Android, they decided not to tell me that they deactivated the one SIM and only one could work. Then after months of horrible service I paid them up , got a settlement letter, gave away their phone and got a new one from a great service provider that is attentive to their customers needs.

Now after a settlement letter was issued, a year later( I paid up in 2021), they are harassing me with endless calls and messages saying that I owe them money. I have never experienced anything like it. This is really outrageous. The worst of all is I emailed them the documents multiple times but as always they do not reply to their mails. Their top management is never available to resolve the issues. The last call they made was yesterday, I was in a board meeting with my directors, their representative(a lady) did not respond kindly to my alerting her that I'm busy. She said"but you answered the phone so you must give me time to speak to you NOW". I AM BEING HARASSED AND IT'S NOT FAIR.