Flight Centre Voucher - ridiculous mark-ups on quotes

I received a R5,000 Flight Centre vouchers as part of my recent Vodacom contracts for a Samsung S8. However, in addtion to making it extremely difficult to activate the offer (I had to send numerous forms back and forth and had to wait for SMSs with codes that never arrived etc), the voucher can only be redeemed via a specific email address to a specific division of Flight Centre. The problem is, their quotes are ~20% more expensive than any of their competitors or even their own Flight Centre stores!! This makes the voucher essentially worthless - TOTAL ****!!