Cell c account.

In 2014 I opened a contract with cell c which also had insurance paid for it monthly after 24 months... I canceled/closed my contract with them because it had reached 24 months... in 2017 I opened a new one used a different phone number than last year I kept on getting emails and phone calls telling me my account is in arreas and I owe cell c money when I go to cell c to check they told me my account is up to date I don't owe any money... Until this one time one of the guys called customer crevice for me they told me I owe R2267. 00 which I don't understand because I paid and closed my contract. And I stopped using that phone number because I had lost my phone years ago and it was after I had paid off and closed my contract.