False marketing !!!

I received a SMS from Markham telling me that I have a R200 voucher. When I went to the store , they said I should buy with R750 or more to qualify for the voucher , but on the sms it never said the voucher was only valid if I buy. This is false marketing, I wasted my time and money and went to Pier 14 Markham to redeem my voucher before expiry but was forced to buy for R750 or more ...... Very disappointed and angry!!