I do not regularly receive Birthday vouchers

In the past I have received a birthday voucher from Makro annually. The past 4 years(this year included) I have not received any vouchers, even though the call centre claims that they have been issued to me. I have confirmed my email and contact information, and still not received anything. It is also claimed that the voucher was used in the previous 3 years,it has only been used by me the past 2 years after I previously complained on Hellopeter, but definitely not by me the owner of the card specified at the other instances. Is this even legal or is it a marketing ****? I have been a regular customer at Makro, since Mr Jocchims was at the old Milnerton Branch, but it seems as if they only offer vouchers to clients that do not regularly purchase there.