Cell C still appears on credit report

I took out a 24 month contract with cell c in 2016, the contract was supposed to end in 2018 May. Due to me calling in late to cancel( according to a cell c agent) it eventually ended in June of 2018. I received my most recent credit report on the 23 March 2019 and I was shocked to see cell c on my credit report. What frustrates me the most was the fact that the installment was even double the amount I was paying when I had the contract previously. I know that removing and account on the credit bearu shouldn’t take an entire year. I would like cell c to remove this as it’s not accurate information. This is affecting my affordability as I already have two other contracts as well so it now makes it three. I am very disappointed as I’ve I never experienced this with other cellular network providers previously. If this is not removed my next step is the Obudsman