Rewards have no rewards

Your Spar Rewards has a major flaw in the system, where your customers get DE*****ED. How can someone else use MY Rewards for Black Friday specials? I never buy coffee.. i couldn't even get 1 coffee for my friend during the Black Friday promotion - because apparently someone has used my cellphone number to make use the Rewards. None of my friends did this. This is *****. Why can a single mom in a single income household not even make use of the Black Friday specials? Why do you allow complete strangers to just say a cellphone number to use someone else's rewards? it defies logic. No other rewards cards work like that. Please change this. I also just wanted ONE washing powder.. NOPE .. someone else had already bought 5 on my rewards. I'm am NOT a happy Spar Rewards customer. You need to re-think how your rewards work.