still being billed for cancelled contracts

I cancelled my Vodacom contracts sometime in January, please see confirmation i got below but I am still being billed for these contracts. Can you please sort it out and refund me for the last 3 months payments taken from account.<br> <br> Dear <br> We apologise for the inconvenience caused. We have process the cancellation and conversion of prepaid of both your lines. This is number *** and *** .<br> <br> The prepaid conversion is an immediate process and takes effect within 24 hours on the termination date or any day thereafter.<br> <br> <br> There are no costs involved when converting to Prepaid.<br> <br> Please make use of all bundled minutes/data as this will be forfeited upon deletion or conversion.<br> <br> <br> Regards,<br> Phindile Chiya