Poor service

On the 13th September 2018 I received the below sms TFG Rewards: Don't forget to redeem ur R50 off R100 voucher before 10 Oct! Present voucher code: 5003A1DBD128716 to redeem at any TFG brand. TsCs.OptOutStop. I then decided to visit Totalsports Hillbrow Johannesburg branch (0n the 1st of October 2018)to purchase a pair of sneakers worth R1 499, I then instructed the guy who was at the counter that I would like to pay R500 in cash and then the rest in account plus this voucher and he agreed, after waiting for too long the guy told me that I must redeem this voucher other time when I come back and the whole amount was done on account because the system took it automatically. REALLY!!! 1. This guy refused to redeem my voucher 2. He also refused to take cash and decided to do what he wanted or thought was good for him. I'm very disappointed.