Cancelation not done after 4 months

I canceled a contract with Mondo in March after their agent misled me by giving me the incorrect information. They listen to the call and found out that I was indeed given the wrong information and they promised to cancel the contract. The router was collected and to date I am still paying for something that I don't have. I am the one who must always call and every time I am told that it is with MTN. I called MTN and there is nothing like that, the account is still active hense I am being debited every month. Mondo customer service is the worsed and the don't care about their customers. Even their team leaders are clueless, I am the one who must always call and be told lies everyday. You will hold in a call for more than 30min and the call get dropped. Imagen paying for months and the company don't even care.