Voucher Not Valid

I bought a voucher at the Boxer Store in Elim mall on 30 December 2015 but when I tried to redeem it. the error message popped on my phone saying the voucher was invalid. I called Hollywood on the 2nd January 2016 seeking to find what was wrong with the voucher and was told to send the picture of my voucher on whatsapp no:*** and someone was gonna attend to it and phone me back. There was no call i received from hollywoodbets. I again on the 6th of January called and was again told to send the picture on whatsapp and the assistance told me she was gonna forward the mail to the person responsible, for them to call me. again there was never a resolution. For third time I called on the 19th of January and followed the same process i followed before and was told someone was gonna call me but to no avail. I am wasting lot of airtime calling these people with no response whatsoever.