Johannesburg officials have apologized to Nelson Mandela after he was sent a warning that his water and electricity could be cut off over an unpaid bill. They said the notice demanding payment of 6,468 rand should have been sent to a different house. City officials have faced a barrage of complaints over bungled utility bills affecting thousands of residents. South Africa's revered former president has been in hospital since June 8 with a recurring lung infection. The notice threatened discontinuation or restriction of services and legal action if the 30-day debt was not paid. However, a city spokesman explained that the address and account number on the notice belonged to another customer and property in a neighboring suburb, not to the Mandela residence. He said the necessary steps would be taken against those behind the mistake.