Handed over for acc that doesn't exist

I Received a call from a rather \lady"named Ntokozo this morning advising me that I have been handed over to them for debt collection. I asked what and who the account was for and was told it was for my RCS credit card. I found this odd since I have not had a credit card for nearly a decade and don't intend on getting one. She couldn't give me any answers (not even an amount) and asked that I please call their offices on ***. I was greeted by someone named Janine (who was not only rude but just as *********** as Nontokozo) and basically told me that the account was handed to them by a company called MBD for collection and that they only handle the collection and don't have any details. So basically I can call them and claim that Eskom has an account with me that hasn't been settled and they'll go ahead and start hounding them without any proof of said debt. I have contacted MBD who don't seem to know what Janine and Ntokozo are talking about"