Refund on flight ticket

I booked my flight return ticket with computicket.com reference 48HV3YK, To Congo Kinshasa return to South Africa dated 30 May 2018 and return 13 June 2018. Due to a court case still pending update, I called computicket and cancelled the trip 28 May 2018 and I was told my ticket still have guarantee period of 1 year but will have to add extra amount accordingly, unfortunately the case still pending not resolved as yet, on the 13 May 2019 I contacted computicket for a refund, I was advised my claim will take 6 to 8 weeks for a refund, I emailed yesterday refund department for a follow-up the advice I will not get any refund as my ticket did have only 6 months grace period in which I wasn't told, I was advised 1 year guarantee period please assist.