Unused showmax voucher is expired without warning

Just spent a hour fighting with showmax on online chat regarding a voucher which I tried to activate. Just to be told it's expired. There is nothing on the voucher, othing in their terms about expiry dates kf vouchers. Yet for some reason I need to take this up with Vodacom as they gave me the voucher!!

How can showmax expire a voucher when they have nothing on terms about validity of voucher, There is nothing on the voucher and the only way to check I presume is to scratch out the silver and reveal the code...

The voucher is in now way Vodacom brabded so not sure why showmax are being so difficult.

Surely you have to at to at least havr the expiry rules online?