Avoid doing business with this company

I attempted to cancel my Fibre Account with Mweb in November last year. I was obstructed at every turn by their rules of engagement for cancellation. Eventually they cancelled my account in February but I neglected to terminate my "recurring monthly payment". I have now paid Mweb 3 months fees for cancelled account. I cannot get my overpayment refunded by them. They keep insisting that I have to prove to them the overpayments were paid by me!!!!!!!!!