Contract cancelled but still billed

I cancelled my contract last year November however I'm still billed. Submitted forms to convert my number to pay as you go which was supposed to happen on 5/12/2019 as per confirmation email received from *** (Nombulelo Mxhonywa Enterprise Support Services-Saves) on 06 November 2019 09:24 AM. Contacted MTN call center & was transferred to 4 different people who can;t assist. Now I'm holding for 1 hour with the answer. the last person I spoke to said my account was refereed to legal & can't give me more details. Worst experience ever sies