On going billing issue with Vodacom

My vodacom account ended being in arrears due to them not debiting on the agreed date.Paid the 2months that was outstanding .Again debit order did not go through for this new month and when I log in my account it shows an ridiculous amount that is still outstanding and I paid that as-well thinking it’s probably additional charges for the missed payments then when I go to check if the account has been updated yet coz I’m unable to connect on the Internet and it shows another ridiculous amount that is outstanding and I’ve tried calling them they keep on referring me to different departments and taking forever to respond to emails.I just want this account to be cancelled and closed and also refund me coz I’ve over paid them.