Vodacom/Samsung/Flight Centre vouchers

Have upgraded my contracts with Vodacom in November 2017. With one of the contract packages I would have received a Flight Centre voucher worth R5000. I received a sms from Vodacom to register the voucher bebore 23 February at 23h59 . I have done this on 21 February and now they dont have proof that I registered. I have contacted Vodacom, Flight Centre and Samsung as this was a promotion from between Samsung and Flight centre. I have send numerous emails to all parties but with no joy. I therefore feel to cancel my one contract as I have not received which I signed for. Bad service according to me.