Correctional Services said that “matters are under control” at Johannesburg’s Sun City Prison on Wed.
A Cell C contract holder almost collapsed when she received a bill for R8891.
Rita Ndumo, of Dobsonville in Soweto, says the account has now escalated to R11358.
Ndumo says she unsuccessfully tried to get an explanation from Cell C as to how she could possibly have called Cointel for three months 24/7?
Cell C has ignored Consumer Line's inquiries and e-mails since November last year.
Ndumo is also concerned that the unfair billing would affect her credit worthiness.
"No sane person can dial a cellphone number continuously for three hours, everyday for three months," says Ndumo.
The itemised bill shows that she made 6896 calls, day and night. All the calls show a zero duration and yet cost R1,75 each.
The 44-page bill for November 2008 shows that at one stage she dialled the number continuously for three hours, which is impossible, Ndumo says.
"This means that I barely slept and made calls for three months all day and all night. My statement shows that I stopped dialling for an hour and then dialled Cointel again continuously from August to October," Ndumo says.
"I thought I made a best choice when I signed up with Cell C, but I now regret it," she says.
Cell C has been investigating the complaint since last November, but would not comment to Consumer Line.
The Independent Communications Authority of South Africa will investigate the matter.