Failure to Refund Premium

ON 5th June I cancelled my vehicle policy No. ***. I was Billed R 389.23 on 1st of June for the monthly premium so I would have expected a refund of the premium paid. On 7th July I sent a email requesting the premium refund and had no response. I emailed again on 21 July and still have had no response. In according to my calculation (389.23 x 12/365*5) a deduction of R 63.98 should have been made for the 5 days the vehicle was still covered so I should receive a refund of R 325.25. I have received nothing so far despite in now being nearly 2 months since I cancelled the policy.