Refusal to exchange Bike after been promised to do so.

I purchased a Raleigh Bike for my son in February and with a short period the seat fell off,the pedals broke, and the chain kept getting stuck.I contacted Raleigh and they advised that I go back to Makro Springfield.I contacted Makro prior to me going there and spoke to the manager of the Sports Department. I explained to him what has happened and that I am bringing in the bike to change it.He agreed and said that I can do that.I called the store on Saturday 19 May 2018 to check if Bonga was there and Hazel confirmed that he is off this weekend.I explained to her what I discussed with Bonga and she requested that I go to the returns department. I went to the Returns department yesterday and was assisted by Londiwe who behaved like she was the expert in accessing this bike.What a grumpy lady.She called the guy from Raleigh and they were having a hearty chat about the bike forgetting that my child could have been injured whilst riding this bike.I then requested to speak to Hazel and she did come to see me at the counter.She saw the bike and even stated that she can see that the bike has not been used extensively and that If Bong has promised and exchange then he must keep to his word. I want this resolved asap.