Paid full price & Can't get complete product

I bought a my son bicycle with a Raleigh brand at Game on the 21st of December 2014 that was supposed to be my son's Christmas present, when I assembled the thing on Christmas, the chain could not stay in the rail because it wasn't straight, went back to Game in January to get a functioning bicycle and I was refused a new bicycle. NB on the customer services queue, I was the only black person and I was the only person that did not get a new item or a refund as there was even an old man that came with a fan bought in August, no one asked him what happened or tested a fan, he was just given his full refund. I accepted policy requirements and accepted that my son will spend another 3 weeks without his bicycle. on Friday the 20th, my wife went to fetch the bicycle which is working fine now but there brake cable and brake pads were removed and never put back again. I do not want to go back to Game Sandton because I was discriminated against the first time and I have to drive from Roodekop for the third time now just to get a proper working R500 bicycle. the manager did not even want to talk to me when I took the bicycle for an exchange. I just want to my son have his toy, please help.