Vodacom's questionable ethics wrt customers

I upgraded my phone on the samsung made for summer promotion. I have a flight redemption code but have now tried for 5 months to make a booking or at the very least get a response on the ********** email address to no avail. I have called flight centre and vodacom and all of them say that there is no contactable person to query my issues with. I am highly frustrated and shocked that I could have possibly been cheated by a company the size of vodacom. It was a mission trying to get the voucher and now it seems all in vain as there is no possible contact to help me with using this voucher. The time limit is also a pressurising issue. The whole situation is simply appalling and has left a very sour taste in my mouth about even dealing with Vodacom or considering any of their promotions every again. I can't help but feel that I should port my number instead of supporting a business with such questionable ethics and to advise as many people as I know to be wary of Vodacom and their "specials" if this situation is not rectifiable.