Bad customer service

I requested a SIM swop but I got hassle after hassle.I then decided in January this year to cancel my MWEB contract by sending emails,only for no one to com back to me. I provided MWEB with a 30 day notice but yet monies were still being taken even after the notice or cancellation request. I managed to do 2 debit order reversals for January and February but the end of March it didn't allow me to. I would like refunds for the times that I have not used the Wifi since last year end Oct,beginning November till current.