Ster kinekor false advertising

Ster kinekor was running a promotion where if you went to the Imax to watch Batman vs superman on March 24th you received a free keyring. When i went to collect mine i was informed by that the cinema only had 20 key rings to give out and they were out of stock . The theatre has plus minus 200 seats so how can they only provide 20 key rings . Its a ploy by the cinema to get people to spend extra money on the Imax Ster Kinekor is a dishonest company and i am absolutely disgusted by their actions. Congratulations you have lost my business