Incorrect demand to pay settled credit card: HP*** / ABSA No Contact - Urgent Notice Plea - ***3

I need urgent intervention. I was previously advised that I qualify for a settlement discount offer for my ABSA credit card which I accordingly paid. To my surprise, I am now contacted by a different collection firm () alleging that I still owe the settled debt. I fail to understand how ABSA has handed over a settled account to different lawyers. This should be urgently resolved