Poor costomer service

I booked a car through travelstart / cartrawler I never used the car hire voucher as bidvest did not want to accept my card my brother had to go to Pretoria and made a complete new booking. I am asking for a full refund of the voucher Booking number ZA ********** 70 I lodged a complaint on their sight ref cas number ********** 7 they also don't answer calls as the call volumes is very high. Please don't use them as there service is very poor. What makes me angry they are very quick to take your money but very reluctant to refund you, never mind to respond to your mails. One last thing is they have a live chat function but this does not work!