Telkom you cause me heartache!

I Received a call from a debt collecting agency who say they represent Telkom. I had no idea what they were trying to claim from me and I actually went to see me credit score on experian and see that Telkom says that I owe them money. I was sequestrated a while back and rehabilitated and Telkom was not listed on the credit bureau anywhere. I lived overseas for a couple of years and recently came back to South Africa. When I asked the person to give me the telephone nr. in question, it was not a number that I know and she could not provide any further information. The same thing happened to my son, who was also Blacklisted due to Telkom. Is this how Telkom operates? I tried so hard to clear my name after the sequestration and now they want to come with all sorts of claims and blacklist me. If it was a Data account or anything like that, did the debt, if there was one, not prescribe after 3 years?