The Nelson Mandela Centre of Memory (NMCM) on Monday denied reports that Mandela owes the City of Johannesburg more than 6,000 rand (about 612 U.S. dollars) and could face legal action if the money was not paid. The Cape Town-based Eyewitness News reported that a pre- termination notice from the City of Johannesburg had been delivered to Mandela\'s house in Houghton in Johannesburg. Dated Aug. 1, the notice advises that the amount has been outstanding for more than 30 days and warns that if it is not paid, or an arrangement is not made to pay it, a \"discontinuation or restriction of services\" will follow, as well as possible legal action, according to the report. The report \"is incorrect\", the NMCM said, adding that the notice might have been delivered to a wrong address. \"I don\'t understand where the story is because it is the wrong address,\" NMCM spokesperson Sello Hatang said. The City of Johannesburg refused to comment on the report. The news came as Mandela spent his 59th day in a Pretoria hospital for treatment of a recurring lung problem. According to the latest official update last week, Mandela remained in a critical but stable condition and continued to show signs of improvement.