Refund the cancelled premature contracts

I prematurely cancelled two contract lines with vodacom in August 2017, during the cancellation, i paid the accounts in full and requested the two lines to be cancelled and not be available on prepaid, to mys surprise the lines were never cancelled and I was billed since for the two lines. All i ask, is Vodacom to pay back the money that they have being billing for the two closed lines and refund the money into my personal account, PLAESE.