Poor Customer Service

I wanted to cancel my Contract with MTN in Februar. A cconsultant told me it takes 3 days for my contract to be cancelled and data is allocated on 12th of every month. I called MTN on 6th March to cancel My Contract and I was told a different story, the consultant who assisted me told me the Contract takes 30 days to be canceled and told me that the 15th March is gonna be my last Debit Order. Jikijiki, I receive a statement from MTN the indicating that my Account is gonna be debited on the 14th April. I called them for Confirmation letter for Contract Cancelation they don't want to give it tome and to enquire about the April Upcoming debit order. They say it is just like that My Account hasto be debited on the 15th April. I don't understand what is happening now because this is contrary to what I was told on the 6th March by MTN consultant. Now I am starting to believe a hear say that MTN does not want their Customers to cancel their contracts. Please help