False Voucher that are not working

I have received voucher for 500 off when I buy over 2000. Am from Maponya mall Fabian I want to buy shoe for 2500 and this shoe is not on sale.They called the customer service and I was told that this voucher are not working they have been experiencing same problem but SMS was sent to us on Monday . Is our Information safe with company driving from home to Maponya mall for nothing . We are getting false voucher .am really so disappointed people need to be aware of voucher received from TFG. All in all our information are not safe If we are receiving things which are not working am not going to leave this am going to the Ombudsman with I have an SMS