Rewards card received but no rewards or vouchers given

I went to ackermans a couple of days ago and purchased for R600 I gave the cashier my rewards card who advised me that i cannot use this anymore it has been cancelled and ackermans will send us the rewards so we can use to buy in store.he can't assist me with a card balance so I phone the helpline and they tell me that i can use my points as it has expired .i have received no sms or emails so how can they cancel without notice and not allow me to use up the points balance I might have...terrible experience