No service delivery

I received an sms from truworths for a R100.00 voucher. I went to truworths store at Benoni Lakeside Mall to use the voucher, but to my shock "I was told the voucher does not exist". This is false advertising and I was kept waiting for more than one hour and felt so embarrassed being asked to provide my personal information more than three times, I felt so humiliated. Can you help me with the Consumer Protection details.