Johannesburg - As 14 Gauteng mayors prepared to meet with the ruling party over billing problems on Thursday, the City of Johannesburg's debt collection agency apologised to consumers for erroneous accounts."We changed IT systems and got a new SMS system. About 100 residents got incorrect accounts. We have sent them SMSs of apology and have now rectified the system," Bernard van Rensburg, director of In-Quest, a debt collecting agency for the council, told The Star newspaper."It is our fault, and not the City of Joburg. It was our stupidity and we do apologise. It was an honest mistake."He was reacting to a picture in the newspaper earlier this week of a consumer, Richard O' Flaherty, who had received an SMS stating he owed the city more than R200 000 000.Van Rensburg said seeing the SMS was "one of the worst days of my life". It turned out the debt collector had confused his nine-digit account number with the amount owing.The report came on the same day the ANC in Gauteng was scheduled to meet with 14 mayors to discuss potholes, billing and flood damage.Last week, Johannesburg mayor Amos Masondo said there was "no crisis" in billing for rates and utilities in the country's economic hub, drawing widespread criticism.Many of the city's customers disagreed after receiving exorbitant bills they said did not reflect true consumption, and after unfair disconnections.The opposition Democratic Alliance has given Masondo a "resounding fail" in a scorecard it drew up for him and his mayoral committee.