Prescribed account

I just received a sms that a letter of demand has been issued for a cell c account that i co-signed on that has been PRESCRIBED more than 3 years ago. According to the NCR If you have not paid any debt for a period of three years, the debt prescribes in terms of the National Credit Act and the Prescription Act. It means the debt is extinguished. It may not be sold or collected upon after it has prescribed. Maybe try and make contact with the actual contract holder? So I want this Collection Company calling on behalf cell c to update the records correctly.