Afrihost debited my account without consent

I called Afrihost to cancel my internet, they said that I will not have to pay this month if I choose not to cancel and I accepted same. Then they tried to debit my account after saying they won’t. I had to reverse the payment. Now they say I have to PAY to get a FREE month. Firstly that is illogical, you don’t make someone pay to get something free and second then I would have rather canceled as the entire point was to not pay this month.