Checkers Christmas Cashback a ****

I visited Checkers Kroonstad on the 28 December as I had received an sms with a R10 voucher on the 26/12. Upon redeeming it, the cashier informed me that her till informs that the voucher is invalid/ already redeemed and I requested to see a supervisor or manager as I never used it. The manager told me that I had to firstly validate the voucher through their call center before visiting the store, secondly, I'm not the only customer being returned because of that reason and thirdly because of the POPI ACT he cannot divulge his name, please bear in mind two managers attended to my query and both of them didn't have name badges and blatantly refused to give me their names. I had to leave the store and contact the call center, used my petrol and airtime and the call center agent advised me that there seemed no problem with my voucher and he promised to issue me with a new one in 24hours.

The voucher is only R10 and I have to jump all this hoops just to redeem it? REALLY Checkers?